Unit C: Expressions, Equations, and Relationships

Topic 4: Using the Pythagorean Theorem

4-1: The Pythagorean Theorem

Key Concept

In a right triangle, the two shortest sides are legs.

The longest side, which is opposite the right angle, is the hypotenuse.

You can represent the lengths of the legs of the triangle with a and b, and the length of the hypotenuse with c.

In any right triangle, the sum of the squares of the lengths of the legs is equal to the square of the length of the hypotenuse. This equation is known as the Pythagorean Theorem.

Part 1

Intro

You can use the Pythagorean Theorem to find the length of the hypotenuse of a right triangle when you know the lengths of the legs.

Example Finding Lengths of Hypotenuses Using the Pythagorean Theorem

What is the length of the hypotenuse of each triangle?

  • a. A right triangle with legs of length 3 cm and 4 cm.


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Table of Contents

Digits, Grade 8, Volume 1, Homework Helper Unit A: Number and Operations Unit B: Proportionality Unit C: Expressions, Equations, and Relationships English/Spanish Glossary Formulas Math Symbols Formulas Measures Properties