Answer:
1. A right triangle is formed when the sum of a^2 and b^2 equals the the square of the hypotenuse. a and b are the supplementary sides and c is the hypotenuse. A right triangle must also have a right angle that is opposite from the hypotenuse.
2. The missing length tends to be the hypotenuse, also known as c^2.
3. You add up the squares of the found sides and then square root the result.
