This proves that the angles of a triangle must add up to 180 degrees. Add the known angles. Form an equation equal to 360˚. Subtract the sum of the known angles from the sum of a complete turn ...

One idea he came up with was a mathematical equation that's used all the ... What it means is that in a right triangle (where one angle equals 90°), the sum of the squares of two sides equals ...

Solutions of quadratic equations (only real roots ... (Motivate) If in two triangles, the corresponding angles are equal, their corresponding sides are proportional and the triangles are similar.