Key Idea: Pythagorean Theorem

The Pythagorean Theorem relates the side lengths of a right triangle:
the square of the hypotenuse equals the sum of the squares of the two legs.

General Rule:

For any right triangle:

a^2+b^2=c^2

where a and b are the legs, and c is the hypotenuse (the side opposite the right angle).

This relationship only applies to right triangles.

Why this matters for the SAT:

The Pythagorean Theorem is used in geometry, coordinate geometry, and word problems involving distance or right triangles.
Recognizing when a triangle is right lets you apply the theorem quickly to find missing side lengths or distances.