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, then 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.
3. The 45-45-90 Triangle4. The 30-60-90 Triangle