Special Triangles

Grade 11s constructed special triangles today. We started with a square with any length sides. We cut it on the diagonal to make an isosceles right triangle. We calculated the length of the hypotenuse, and the acute angles (both 45 degrees), then we wrote the simplified trigonometric ratios.

We did the same with an equilateral triangle, sliced in half to create a 30, 60, 90 triangle. We calculated the height of the triangle, and then wrote out all of the simplified trig ratios for each acute angle.

We have engraved these special triangles into our memory, bu even if we forget, hopefully the derivation of them will stick in our memory and we could do it again if we needed to.