Added cells for notebook exercise

module2/exo1/toy_notebook_en.ipynb

 {
- "cells": [],
+ "cells": ["cells": [
+  {
+    "cell_type": "markdown",
+    "metadata": {},
+    "source": [
+      "# À propos de pi"
+    ]
+  },
+  {
+    "cell_type": "markdown",
+    "metadata": {},
+    "source": [
+      "Some mathematical formulas:\n",
+      "$\\pi = \\frac{C}{D}$\n",
+      "$$ \\pi \\approx 3.14 $$"
+    ]
+  },
+  {
+    "cell_type": "code",
+    "execution_count": null,
+    "metadata": {},
+    "outputs": [],
+    "source": [
+      "import math\n",
+      "print(math.pi)"
+    ]
+  },
+  {
+    "cell_type": "markdown",
+    "metadata": {},
+    "source": [
+      "Learn more here: [Aiguilles de Buffon](https://fr.wikipedia.org/wiki/Aiguille_de_Buffon)"
+    ]
+  },
+  {
+    "cell_type": "code",
+    "execution_count": null,
+    "metadata": {},
+    "outputs": [],
+    "source": [
+      "import random\n",
+      "import math\n\n",
+      "def buffon_needle(n):\n",
+      "    count = 0\n",
+      "    for _ in range(n):\n",
+      "        x = random.uniform(0, 1)\n",
+      "        theta = random.uniform(0, math.pi / 2)\n",
+      "        if x <= math.sin(theta):\n",
+      "            count += 1\n",
+      "    return (2 * n) / count\n\n",
+      "print(buffon_needle(100000))"
+    ]
+  },
+  {
+    "cell_type": "code",
+    "execution_count": null,
+    "metadata": {},
+    "outputs": [],
+    "source": [
+      "import matplotlib.pyplot as plt\n",
+      "import numpy as np\n\n",
+      "x = np.linspace(0, 2 * np.pi, 100)\n",
+      "y = np.sin(x)\n\n",
+      "plt.plot(x, y)\n",
+      "plt.title(\"Sine Wave\")\n",
+      "plt.xlabel(\"x\")\n",
+      "plt.ylabel(\"sin(x)\")\n",
+      "plt.grid(True)\n",
+      "plt.show()"
+    ]
+  }
+]
+],
  "metadata": {
   "kernelspec": {
    "display_name": "Python 3",