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### Using the Pythagorean Theorem

• A right triangle is a triangle with one right, 90°, angle. It has two legs, which are the shorter sides. The hypotenuse is the longest side and is the diagonal; it‘s the side across from the right angle.
• The Pythagorean Theorem, a2 + b2 = c2, shows how the lengths of the sides in a right triangle are related. The sum of the squares of the legs is equal to the hypotenuse.
• The letters a, b, and c are commonly used to represent the sides of a right triangle. a and b are used to represent the legs and c is used to represent the hypotenuse.
• You can use different forms of the Pythagorean Theorem to find the measurement of either leg, or the hypotenuse.
• You can use the Pythagorean Theorem to determine whether a triangle is a right triangle. If the sum of the squares of the legs does not equal the hypotenuse the triangle is not a right triangle.

## Using the Pythagorean Theorem

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