diff --git a/travail_pratique/vec2/Makefile b/travail_pratique/vec2/Makefile
new file mode 100644
index 0000000000000000000000000000000000000000..668479bb412752e4dce1aa76668a6a5818307240
--- /dev/null
+++ b/travail_pratique/vec2/Makefile
@@ -0,0 +1,15 @@
+CC=gcc
+OPTS=-g -O3 -Wall -Wextra
+LINK=-lm
+
+main: main.o vec2.o
+	$(CC) $(OPTS) -o $@ $^ $(LINK)
+
+main.o: main.c
+	$(CC) $(OPTS) -c $^
+
+vec2.o: vec2.c vec2.h
+	$(CC) $(OPTS) -c $^
+
+clean:
+	rm -f *.o main
\ No newline at end of file
diff --git a/travail_pratique/vec2/main.c b/travail_pratique/vec2/main.c
new file mode 100644
index 0000000000000000000000000000000000000000..841254d8ffc8a1b67585b76d3d42fdac1b16fece
--- /dev/null
+++ b/travail_pratique/vec2/main.c
@@ -0,0 +1,15 @@
+#include <stdlib.h>
+#include "vec2.h"
+
+int main() {
+    vec2 v1 = vec2_create(1.0, -1.0);
+    // vec2_print(v1);
+    vec2 v2 = vec2_create(4.0, -2.0);
+    // vec2_print(v2);
+
+    vec2 v3 = vec2_sub(v1, v2);
+
+    vec2_print(v3);
+
+    return EXIT_SUCCESS;
+}
\ No newline at end of file
diff --git a/travail_pratique/vec2/tests/Makefile b/travail_pratique/vec2/tests/Makefile
new file mode 100644
index 0000000000000000000000000000000000000000..7966f6f8a76f80097d934809e74b7e8c1550448a
--- /dev/null
+++ b/travail_pratique/vec2/tests/Makefile
@@ -0,0 +1,18 @@
+CC=gcc
+OPTS=-g -O3 -Wall -Wextra
+LINK=-lm
+
+vec2_tests: vec2_tests.o vec2.o
+	$(CC) $(OPTS) -o $@ $^ $(LINK)
+
+test: vec2_tests
+	./vec2_tests
+
+vec2_tests.o: vec2_tests.c
+	$(CC) $(OPTS) -c $^
+
+vec2.o: ../vec2.c ../vec2.h
+	$(CC) $(OPTS) -c $^
+
+clean:
+	rm -f *.o vec2_tests
\ No newline at end of file
diff --git a/travail_pratique/vec2/tests/minunit.h b/travail_pratique/vec2/tests/minunit.h
new file mode 100644
index 0000000000000000000000000000000000000000..b716888b4da4fc251b3a4bea25acda44f1a6fafb
--- /dev/null
+++ b/travail_pratique/vec2/tests/minunit.h
@@ -0,0 +1,391 @@
+/*
+ * Copyright (c) 2012 David Siñuela Pastor, siu.4coders@gmail.com
+ * 
+ * Permission is hereby granted, free of charge, to any person obtaining
+ * a copy of this software and associated documentation files (the
+ * "Software"), to deal in the Software without restriction, including
+ * without limitation the rights to use, copy, modify, merge, publish,
+ * distribute, sublicense, and/or sell copies of the Software, and to
+ * permit persons to whom the Software is furnished to do so, subject to
+ * the following conditions:
+ * 
+ * The above copyright notice and this permission notice shall be
+ * included in all copies or substantial portions of the Software.
+ * 
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+ * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
+ * LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
+ * OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+ * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ */
+#ifndef MINUNIT_MINUNIT_H
+#define MINUNIT_MINUNIT_H
+
+#ifdef __cplusplus
+	extern "C" {
+#endif
+
+#if defined(_WIN32)
+#include <Windows.h>
+#if defined(_MSC_VER) && _MSC_VER < 1900
+  #define snprintf _snprintf
+  #define __func__ __FUNCTION__
+#endif
+
+#elif defined(__unix__) || defined(__unix) || defined(unix) || (defined(__APPLE__) && defined(__MACH__))
+
+/* Change POSIX C SOURCE version for pure c99 compilers */
+#if !defined(_POSIX_C_SOURCE) || _POSIX_C_SOURCE < 200112L
+#undef _POSIX_C_SOURCE
+#define _POSIX_C_SOURCE 200112L
+#endif
+
+#include <unistd.h>	/* POSIX flags */
+#include <time.h>	/* clock_gettime(), time() */
+#include <sys/time.h>	/* gethrtime(), gettimeofday() */
+#include <sys/resource.h>
+#include <sys/times.h>
+#include <string.h>
+
+#if defined(__MACH__) && defined(__APPLE__)
+#include <mach/mach.h>
+#include <mach/mach_time.h>
+#endif
+
+#if __GNUC__ >= 5 && !defined(__STDC_VERSION__)
+#define __func__ __extension__ __FUNCTION__
+#endif
+
+#else
+#error "Unable to define timers for an unknown OS."
+#endif
+
+#include <stdio.h>
+#include <math.h>
+
+/*  Maximum length of last message */
+#define MINUNIT_MESSAGE_LEN 1024
+/*  Accuracy with which floats are compared */
+#define MINUNIT_EPSILON 1E-12
+
+/*  Misc. counters */
+static int minunit_run = 0;
+static int minunit_assert = 0;
+static int minunit_fail = 0;
+static int minunit_status = 0;
+
+/*  Timers */
+static double minunit_real_timer = 0;
+static double minunit_proc_timer = 0;
+
+/*  Last message */
+static char minunit_last_message[MINUNIT_MESSAGE_LEN];
+
+/*  Test setup and teardown function pointers */
+static void (*minunit_setup)(void) = NULL;
+static void (*minunit_teardown)(void) = NULL;
+
+/*  Definitions */
+#define MU_TEST(method_name) static void method_name(void)
+#define MU_TEST_SUITE(suite_name) static void suite_name(void)
+
+#define MU__SAFE_BLOCK(block) do {\
+	block\
+} while(0)
+
+/*  Run test suite and unset setup and teardown functions */
+#define MU_RUN_SUITE(suite_name) MU__SAFE_BLOCK(\
+	suite_name();\
+	minunit_setup = NULL;\
+	minunit_teardown = NULL;\
+)
+
+/*  Configure setup and teardown functions */
+#define MU_SUITE_CONFIGURE(setup_fun, teardown_fun) MU__SAFE_BLOCK(\
+	minunit_setup = setup_fun;\
+	minunit_teardown = teardown_fun;\
+)
+
+/*  Test runner */
+#define MU_RUN_TEST(test) MU__SAFE_BLOCK(\
+	if (minunit_real_timer==0 && minunit_proc_timer==0) {\
+		minunit_real_timer = mu_timer_real();\
+		minunit_proc_timer = mu_timer_cpu();\
+	}\
+	if (minunit_setup) (*minunit_setup)();\
+	minunit_status = 0;\
+	test();\
+	minunit_run++;\
+	if (minunit_status) {\
+		minunit_fail++;\
+		printf("F");\
+		printf("\n%s\n", minunit_last_message);\
+	}\
+	fflush(stdout);\
+	if (minunit_teardown) (*minunit_teardown)();\
+)
+
+/*  Report */
+#define MU_REPORT() MU__SAFE_BLOCK(\
+	double minunit_end_real_timer;\
+	double minunit_end_proc_timer;\
+	printf("\n\n%d tests, %d assertions, %d failures\n", minunit_run, minunit_assert, minunit_fail);\
+	minunit_end_real_timer = mu_timer_real();\
+	minunit_end_proc_timer = mu_timer_cpu();\
+	printf("\nFinished in %.8f seconds (real) %.8f seconds (proc)\n\n",\
+		minunit_end_real_timer - minunit_real_timer,\
+		minunit_end_proc_timer - minunit_proc_timer);\
+)
+#define MU_EXIT_CODE minunit_fail
+
+/*  Assertions */
+#define mu_check(test) MU__SAFE_BLOCK(\
+	minunit_assert++;\
+	if (!(test)) {\
+		snprintf(minunit_last_message, MINUNIT_MESSAGE_LEN, "%s failed:\n\t%s:%d: %s", __func__, __FILE__, __LINE__, #test);\
+		minunit_status = 1;\
+		return;\
+	} else {\
+		printf(".");\
+	}\
+)
+
+#define mu_fail(message) MU__SAFE_BLOCK(\
+	minunit_assert++;\
+	snprintf(minunit_last_message, MINUNIT_MESSAGE_LEN, "%s failed:\n\t%s:%d: %s", __func__, __FILE__, __LINE__, message);\
+	minunit_status = 1;\
+	return;\
+)
+
+#define mu_assert(test, message) MU__SAFE_BLOCK(\
+	minunit_assert++;\
+	if (!(test)) {\
+		snprintf(minunit_last_message, MINUNIT_MESSAGE_LEN, "%s failed:\n\t%s:%d: %s", __func__, __FILE__, __LINE__, message);\
+		minunit_status = 1;\
+		return;\
+	} else {\
+		printf(".");\
+	}\
+)
+
+#define mu_assert_int_eq(expected, result) MU__SAFE_BLOCK(\
+	int minunit_tmp_e;\
+	int minunit_tmp_r;\
+	minunit_assert++;\
+	minunit_tmp_e = (expected);\
+	minunit_tmp_r = (result);\
+	if (minunit_tmp_e != minunit_tmp_r) {\
+		snprintf(minunit_last_message, MINUNIT_MESSAGE_LEN, "%s failed:\n\t%s:%d: %d expected but was %d", __func__, __FILE__, __LINE__, minunit_tmp_e, minunit_tmp_r);\
+		minunit_status = 1;\
+		return;\
+	} else {\
+		printf(".");\
+	}\
+)
+
+#define mu_assert_double_eq(expected, result) MU__SAFE_BLOCK(\
+	double minunit_tmp_e;\
+	double minunit_tmp_r;\
+	minunit_assert++;\
+	minunit_tmp_e = (expected);\
+	minunit_tmp_r = (result);\
+	if (fabs(minunit_tmp_e-minunit_tmp_r) > MINUNIT_EPSILON) {\
+		int minunit_significant_figures = 1 - log10(MINUNIT_EPSILON);\
+		snprintf(minunit_last_message, MINUNIT_MESSAGE_LEN, "%s failed:\n\t%s:%d: %.*g expected but was %.*g", __func__, __FILE__, __LINE__, minunit_significant_figures, minunit_tmp_e, minunit_significant_figures, minunit_tmp_r);\
+		minunit_status = 1;\
+		return;\
+	} else {\
+		printf(".");\
+	}\
+)
+
+#define mu_assert_string_eq(expected, result) MU__SAFE_BLOCK(\
+	const char* minunit_tmp_e = expected;\
+	const char* minunit_tmp_r = result;\
+	minunit_assert++;\
+	if (!minunit_tmp_e) {\
+		minunit_tmp_e = "<null pointer>";\
+	}\
+	if (!minunit_tmp_r) {\
+		minunit_tmp_r = "<null pointer>";\
+	}\
+	if(strcmp(minunit_tmp_e, minunit_tmp_r)) {\
+		snprintf(minunit_last_message, MINUNIT_MESSAGE_LEN, "%s failed:\n\t%s:%d: '%s' expected but was '%s'", __func__, __FILE__, __LINE__, minunit_tmp_e, minunit_tmp_r);\
+		minunit_status = 1;\
+		return;\
+	} else {\
+		printf(".");\
+	}\
+)
+
+/*
+ * The following two functions were written by David Robert Nadeau
+ * from http://NadeauSoftware.com/ and distributed under the
+ * Creative Commons Attribution 3.0 Unported License
+ */
+
+/**
+ * Returns the real time, in seconds, or -1.0 if an error occurred.
+ *
+ * Time is measured since an arbitrary and OS-dependent start time.
+ * The returned real time is only useful for computing an elapsed time
+ * between two calls to this function.
+ */
+static double mu_timer_real(void)
+{
+#if defined(_WIN32)
+	/* Windows 2000 and later. ---------------------------------- */
+	LARGE_INTEGER Time;
+	LARGE_INTEGER Frequency;
+	
+	QueryPerformanceFrequency(&Frequency);
+	QueryPerformanceCounter(&Time);
+	
+	Time.QuadPart *= 1000000;
+	Time.QuadPart /= Frequency.QuadPart;
+	
+	return (double)Time.QuadPart / 1000000.0;
+
+#elif (defined(__hpux) || defined(hpux)) || ((defined(__sun__) || defined(__sun) || defined(sun)) && (defined(__SVR4) || defined(__svr4__)))
+	/* HP-UX, Solaris. ------------------------------------------ */
+	return (double)gethrtime( ) / 1000000000.0;
+
+#elif defined(__MACH__) && defined(__APPLE__)
+	/* OSX. ----------------------------------------------------- */
+	static double timeConvert = 0.0;
+	if ( timeConvert == 0.0 )
+	{
+		mach_timebase_info_data_t timeBase;
+		(void)mach_timebase_info( &timeBase );
+		timeConvert = (double)timeBase.numer /
+			(double)timeBase.denom /
+			1000000000.0;
+	}
+	return (double)mach_absolute_time( ) * timeConvert;
+
+#elif defined(_POSIX_VERSION)
+	/* POSIX. --------------------------------------------------- */
+	struct timeval tm;
+#if defined(_POSIX_TIMERS) && (_POSIX_TIMERS > 0)
+	{
+		struct timespec ts;
+#if defined(CLOCK_MONOTONIC_PRECISE)
+		/* BSD. --------------------------------------------- */
+		const clockid_t id = CLOCK_MONOTONIC_PRECISE;
+#elif defined(CLOCK_MONOTONIC_RAW)
+		/* Linux. ------------------------------------------- */
+		const clockid_t id = CLOCK_MONOTONIC_RAW;
+#elif defined(CLOCK_HIGHRES)
+		/* Solaris. ----------------------------------------- */
+		const clockid_t id = CLOCK_HIGHRES;
+#elif defined(CLOCK_MONOTONIC)
+		/* AIX, BSD, Linux, POSIX, Solaris. ----------------- */
+		const clockid_t id = CLOCK_MONOTONIC;
+#elif defined(CLOCK_REALTIME)
+		/* AIX, BSD, HP-UX, Linux, POSIX. ------------------- */
+		const clockid_t id = CLOCK_REALTIME;
+#else
+		const clockid_t id = (clockid_t)-1;	/* Unknown. */
+#endif /* CLOCK_* */
+		if ( id != (clockid_t)-1 && clock_gettime( id, &ts ) != -1 )
+			return (double)ts.tv_sec +
+				(double)ts.tv_nsec / 1000000000.0;
+		/* Fall thru. */
+	}
+#endif /* _POSIX_TIMERS */
+
+	/* AIX, BSD, Cygwin, HP-UX, Linux, OSX, POSIX, Solaris. ----- */
+	gettimeofday( &tm, NULL );
+	return (double)tm.tv_sec + (double)tm.tv_usec / 1000000.0;
+#else
+	return -1.0;		/* Failed. */
+#endif
+}
+
+/**
+ * Returns the amount of CPU time used by the current process,
+ * in seconds, or -1.0 if an error occurred.
+ */
+static double mu_timer_cpu(void)
+{
+#if defined(_WIN32)
+	/* Windows -------------------------------------------------- */
+	FILETIME createTime;
+	FILETIME exitTime;
+	FILETIME kernelTime;
+	FILETIME userTime;
+
+	/* This approach has a resolution of 1/64 second. Unfortunately, Windows' API does not offer better */
+	if ( GetProcessTimes( GetCurrentProcess( ),
+		&createTime, &exitTime, &kernelTime, &userTime ) != 0 )
+	{
+		ULARGE_INTEGER userSystemTime;
+		memcpy(&userSystemTime, &userTime, sizeof(ULARGE_INTEGER));
+		return (double)userSystemTime.QuadPart / 10000000.0;
+	}
+
+#elif defined(__unix__) || defined(__unix) || defined(unix) || (defined(__APPLE__) && defined(__MACH__))
+	/* AIX, BSD, Cygwin, HP-UX, Linux, OSX, and Solaris --------- */
+
+#if defined(_POSIX_TIMERS) && (_POSIX_TIMERS > 0)
+	/* Prefer high-res POSIX timers, when available. */
+	{
+		clockid_t id;
+		struct timespec ts;
+#if _POSIX_CPUTIME > 0
+		/* Clock ids vary by OS.  Query the id, if possible. */
+		if ( clock_getcpuclockid( 0, &id ) == -1 )
+#endif
+#if defined(CLOCK_PROCESS_CPUTIME_ID)
+			/* Use known clock id for AIX, Linux, or Solaris. */
+			id = CLOCK_PROCESS_CPUTIME_ID;
+#elif defined(CLOCK_VIRTUAL)
+			/* Use known clock id for BSD or HP-UX. */
+			id = CLOCK_VIRTUAL;
+#else
+			id = (clockid_t)-1;
+#endif
+		if ( id != (clockid_t)-1 && clock_gettime( id, &ts ) != -1 )
+			return (double)ts.tv_sec +
+				(double)ts.tv_nsec / 1000000000.0;
+	}
+#endif
+
+#if defined(RUSAGE_SELF)
+	{
+		struct rusage rusage;
+		if ( getrusage( RUSAGE_SELF, &rusage ) != -1 )
+			return (double)rusage.ru_utime.tv_sec +
+				(double)rusage.ru_utime.tv_usec / 1000000.0;
+	}
+#endif
+
+#if defined(_SC_CLK_TCK)
+	{
+		const double ticks = (double)sysconf( _SC_CLK_TCK );
+		struct tms tms;
+		if ( times( &tms ) != (clock_t)-1 )
+			return (double)tms.tms_utime / ticks;
+	}
+#endif
+
+#if defined(CLOCKS_PER_SEC)
+	{
+		clock_t cl = clock( );
+		if ( cl != (clock_t)-1 )
+			return (double)cl / (double)CLOCKS_PER_SEC;
+	}
+#endif
+
+#endif
+
+	return -1;		/* Failed. */
+}
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* MINUNIT_MINUNIT_H */
diff --git a/travail_pratique/vec2/tests/vec2_tests.c b/travail_pratique/vec2/tests/vec2_tests.c
new file mode 100644
index 0000000000000000000000000000000000000000..49af2f20c8fad82a3da059174b0110064f80fc81
--- /dev/null
+++ b/travail_pratique/vec2/tests/vec2_tests.c
@@ -0,0 +1,117 @@
+#include "minunit.h"
+#include "../vec2.h"
+
+static vec2 four_two;
+static vec2 minus_three_nine;
+static vec2 e_x;
+static vec2 e_y;
+static double alpha = 0.0;
+
+
+void test_setup(void) {
+    four_two = vec2_create(4.0, 2.0);
+    minus_three_nine = vec2_create(-3.0, 9.0);
+
+    e_x =  vec2_create(1.0, 0.0);
+    e_y =  vec2_create(0.0, 1.0);
+
+    alpha = 1.5;
+}
+
+void test_teardown(void) {
+	/* Nothing */
+}
+
+MU_TEST(test_vec2_create) {
+	mu_assert_double_eq(four_two.x, 4.0);
+	mu_assert_double_eq(four_two.y, 2.0);
+    mu_assert(vec2_is_approx_equal(four_two, vec2_create(4.0, 2.0), MINUNIT_EPSILON), "four_two should be (4.0, 2.0).");
+
+	mu_assert_double_eq(minus_three_nine.x, -3.0);
+	mu_assert_double_eq(minus_three_nine.y,  9.0);
+
+	mu_assert_double_eq(e_x.x, 1.0);
+	mu_assert_double_eq(e_x.y, 0.0);
+
+	mu_assert_double_eq(e_y.x, 0.0);
+	mu_assert_double_eq(e_y.y, 1.0);
+}
+
+MU_TEST(test_vec2_add) {
+    mu_assert(
+        vec2_is_approx_equal(
+            vec2_add(four_two, minus_three_nine), 
+            vec2_create(1.0, 11.0), MINUNIT_EPSILON), 
+        "(4,2)+(-3,9)=(1, 11)."
+    );
+    mu_assert(
+        vec2_is_approx_equal(
+            vec2_add(four_two, minus_three_nine), 
+            vec2_add(minus_three_nine, four_two), MINUNIT_EPSILON), 
+        "Addition is commutative."
+    );
+}
+
+MU_TEST(test_vec2_sub) {
+    mu_assert(
+        vec2_is_approx_equal(
+            vec2_sub(four_two, minus_three_nine), 
+            vec2_create(7.0, -7.0), MINUNIT_EPSILON), 
+        "(4,2)-(-3,9)=(7, -7)."
+    );
+
+    mu_assert(
+        vec2_is_approx_equal(
+            vec2_sub(four_two, minus_three_nine), 
+            vec2_add(four_two, vec2_mul(-1.0, minus_three_nine)), MINUNIT_EPSILON), 
+        "(4,2) - (-3,9) = (4,2) + (-1) * (-3,9)."
+    );
+}
+
+MU_TEST(test_vec2_mul) {
+    mu_assert(
+        vec2_is_approx_equal(
+            vec2_mul(alpha, minus_three_nine), 
+            vec2_create(-4.5, 13.5), MINUNIT_EPSILON), 
+        "1.5 * (-3,9)=(-4.5, 13.5)."
+    );
+
+    mu_assert(
+        vec2_is_approx_equal(
+            vec2_add(vec2_mul(4.0, e_x), vec2_mul(2.0, e_y)), 
+            four_two, MINUNIT_EPSILON), 
+        "4 * (1,0) + 2 * (0,1) = (4,2)."
+    );
+}
+
+
+
+MU_TEST(test_vec2_scalar_product) {
+    mu_assert_double_eq(
+        vec2_scalar_product(four_two, minus_three_nine), 
+        6.0
+    );
+
+    mu_assert_double_eq(
+        vec2_scalar_product(e_x, e_y), 
+        0.0
+    );
+}
+
+MU_TEST_SUITE(test_suite) {
+	MU_SUITE_CONFIGURE(&test_setup, &test_teardown);
+
+	MU_RUN_TEST(test_vec2_create);
+
+	MU_RUN_TEST(test_vec2_add);
+	MU_RUN_TEST(test_vec2_sub);
+	MU_RUN_TEST(test_vec2_mul);
+	MU_RUN_TEST(test_vec2_scalar_product);
+}
+
+int main() {
+	MU_RUN_SUITE(test_suite);
+	MU_REPORT();
+	return MU_EXIT_CODE;
+}
+
diff --git a/travail_pratique/vec2/vec2.c b/travail_pratique/vec2/vec2.c
new file mode 100644
index 0000000000000000000000000000000000000000..a2b787e6ee07f5ce9d9e79dda930ea7df5a0f221
--- /dev/null
+++ b/travail_pratique/vec2/vec2.c
@@ -0,0 +1,49 @@
+#include <stdio.h>
+#include <math.h>
+#include "vec2.h"
+
+vec2 vec2_create(double x_, double y_) {
+    vec2 v = {.x = x_, .y = y_};
+    return v;
+}
+
+vec2 vec2_add(vec2 lhs, vec2 rhs) {
+    return vec2_create(
+        lhs.x + rhs.x,
+        lhs.y + rhs.y
+    );
+}
+
+vec2 vec2_sub(vec2 lhs, vec2 rhs) {
+    return vec2_create(
+        lhs.x - rhs.x,
+        lhs.y - rhs.y
+    );
+}
+
+vec2 vec2_mul(double scalar, vec2 lhs) {
+    return vec2_create(
+        scalar * lhs.x,
+        scalar * lhs.y
+    );
+}
+
+double vec2_scalar_product(vec2 lhs, vec2 rhs) {
+    return lhs.x * rhs.x + lhs.y * rhs.y;
+}
+
+double vec2_norm_sqr(vec2 v) {
+    return vec2_scalar_product(v, v);
+}
+
+double vec2_norm(vec2 v) {
+    return sqrt(vec2_norm_sqr(v));
+}
+
+bool vec2_is_approx_equal(vec2 lhs, vec2 rhs, double eps) {
+    return vec2_norm(vec2_sub(lhs, rhs)) < eps;
+}
+
+void vec2_print(vec2 v) {
+    printf("x = %f, y = %f\n", v.x, v.y);
+}
\ No newline at end of file
diff --git a/travail_pratique/vec2/vec2.h b/travail_pratique/vec2/vec2.h
new file mode 100644
index 0000000000000000000000000000000000000000..d90a580b008471dcebb573ba40ae2834ec64b8b7
--- /dev/null
+++ b/travail_pratique/vec2/vec2.h
@@ -0,0 +1,28 @@
+#ifndef _VEC2_H_
+#define _VEC2_H_
+
+#include <stdbool.h>
+
+typedef struct _vec2 {
+    double x, y;
+} vec2;
+
+vec2 vec2_create(double x_, double y_);
+
+vec2 vec2_add(vec2 lhs, vec2 rhs);
+
+vec2 vec2_sub(vec2 lhs, vec2 rhs);
+
+vec2 vec2_mul(double scalar, vec2 lhs);
+
+double vec2_scalar_product(vec2 lhs, vec2 rhs);
+
+double vec2_norm_sqr(vec2 v);
+
+double vec2_norm(vec2 v);
+
+bool vec2_is_approx_equal(vec2 lhs, vec2 rhs, double eps);
+
+void vec2_print(vec2 v);
+
+#endif
\ No newline at end of file