Update 02_math_recap_linear_algebra.ipynb

Correction on page 21: aligned --> orthogonal
Correction on page 21: added "degrees" at the end of angles

AA2324/course/02_math_recap_linear_algebra/02_math_recap_linear_algebra.ipynb

@@ -2838,15 +2838,15 @@
     "\n",
     "![The matrix $\\mathbf{A}$ again distorting the grid.  This time, I want to draw particular attention to what happens to the highlighted square.](https://raw.githubusercontent.com/d2l-ai/d2l-en/master/img/grid-transform-filled.svg)\n",
     "\n",
-    "**Sanity Check:** We cannot apply Pythagoras Theorem to compute area because axes are not aligned anymore.\n",
+    "**Sanity Check:** We cannot apply Pythagoras Theorem to compute area because axes are not orthogonal anymore.\n",
     "\n",
-    "The picture is misleading since the axis is **CLOSED to be aligned**.\n",
+    "The picture is misleading since the axis is **CLOSED to be orthogonal**.\n",
     "\n",
-    "The angle between $[1, -1]$ and $[2,3]$ is 101.30993247402021\n",
+    "The angle between $[1, -1]$ and $[2,3]$ is 101.30993247402021 degrees\n",
     "```python import numpy as np; X = np.array([[1, -1], [2, 3]]);thetarad = angle(X[0,:],X[1,:]);theta = thetarad*180/np.pi; print(theta)}}\n",
     "```\n",
     "\n",
-    "The angle between $[1, 0]$ and $[0, 1]$ is 90.\n",
+    "The angle between $[1, 0]$ and $[0, 1]$ is 90 degrees.\n",
     "\n",
     "```python\n",
     "is_basis = False\n",