To solve this, use the Pythagorean Theorem, a² + b² = c², where a and b are the legs of the right triangle, and c is the hypotenuse of the right triangle. **The Pythagorean Theorem only works for right triangles.**
Substitute in the values. a² + b² = c² 12² + 16² = c²
Solve for c, the hypotenuse. 12² + 16² = c² 144 + 256 = c² 400 = c² c = √400 c = 20
