The Pythagorean Theorem

The Right Idea

Besides a 90 degree angle, all right triangles have something else in common: there is a consistent relationship between their sides. This relationship is described by a well known formula, the Pythagorean theorem.

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The Pythagorean theorem, which states that the sum of the squares of a right triangle's legs is equivalent to the square of its hypotenuse, can be used to find the length of a side of a right triangle when given the other two sides.

Watch the Virtual GED Class video below for a complete explanation and tons of worked example problems. Refer to your GED Formula sheet and print out the example problems to follow along with the video lesson.


Solve for the missing side of a right triangle on Khan Academy.

Mixed Pythagorean theorem problems with rounding from Kuta Software.

Pythagorean theorem application problems from Khan Academy.


Example 1

Example 2

Example 3

Example 4

Example 5

Extension 1