In the right triangle shown, one leg is 30 and the hypotenuse is 50. This is 10
times 3-4-5. The other leg is 40.
5-12-13 triangles: If a right triangle’s leg-to-leg ratio is 5:12, or if the leg-to-
hypotenuse ratio is 5:13 or 12:13, then it’s a 5-12-13 triangle, and you don’t
need to use the Pythagorean theorem to find the third side. Just figure out
what multiple of 5-12-13 it is.
Here one leg is 36 and the hypotenuse is 39. This is 3 times 5-12-13. The other
leg is 3 × 5 or 15.
45-45-90 triangles: The sides of a 45-45-90 triangle are in a ratio of