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Finding the Hypotenuse

Part of the Triangles section of Coddy's Geometry journey. Lesson 24 of 63.

Knowing the two legs, the theorem gives the hypotenuse. Square the legs, add them, and take the square root.

Right triangle PQR with legs 8 and 6

Here the legs are 8 and 6: 8^2 + 6^2 = 64 + 36, which is 100. So c^2 = 100 and c = 10, because 10 × 10 = 100. Only the positive root counts: a length is never negative.

On the stage, tap the hypotenuse and pick Pythagorean theorem. The board checks that the triangle has a right angle before it uses the rule.

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Challenge

△ABC has a right angle at A. Find the hypotenuse BC, then press Check.

Try it yourself

Find the marked part of the figure

Find the marked part of the figure

quiz iconTest yourself

This lesson includes a short quiz. Start the lesson to answer it and track your progress.

All lessons in Triangles