Geometry · Similarity & Right Triangles
Pythagorean Theorem
HSG-SRT.C.8
Definition
In a right triangle, a2 + b2 = c2, where c is the hypotenuse.
Examples
- 32 + 42 = 9 + 16 = 25 = 52, so c = 5.
- 62 + 82 = 36 + 64 = 100 = 102, so c = 10.
Key rule
The Pythagorean theorem only works for right triangles, and c is always the hypotenuse.
Memory hook
a2 + b2 = c2, right triangles only.