(leg 1 )^2 + (leg 2 )^2 = (hypotenuse)^2If one leg is 2 and the other leg is 3, then:
85 . The 3-4-5 Triangle
If a right triangle’s leg-to-leg ratio is 3:4, or if the leg-to-hypotenuse ratio is 3:5 or 4:5, it’s a 3-4-5
triangle, and you don’t need to use the Pythagorean theorem to find the third side. Just figure
out what multiple of 3-4-5 it is.
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.
86 . The 5-12-13 Triangle
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 15.