What I learned in this week is about right triangles with the Pythagorean theorem.

A lot of people in grade 10 already know the Pythagorean theorem. It is only used in right triangles, and the other theories are even used in only right triangles. There is opposite, adjacent, and hypotenuse in right triangles. They are titles of sides of right triangles, adjacent means which have two angles, 90 degrees, and unknown angle or that we already know. Hypotenuse defines slanted side which does not have 90 degrees. Opposite defines another angle. the formulas of right triangles are 3, they are sin, cos, and tan.

sin = opposite/hypotenuse (SOH), cos = adjacent/hypotenuse (CAH), and tan = opposite/adjacent.

(The opposite is always top, and the hypotenuse is always the bottom.)