Right Triangles

Part of the Angles section of Coddy's Geometry journey. Lesson 45 of 62.

A right triangle has one angle of 90°. Since its three angles add to 180°, the other two add to 90° and are complementary.

$A right triangle with the right angle at the apex and a 28 degree base angle$

The square marks a 90° angle. The other two angles must therefore satisfy 28 + y = 90, giving y = 62.

Challenge

Medium

The triangle in the figure is right-angled at the apex. One base angle measures 38°, the other x°.

$A right triangle with the right angle at the apex, base angles 38 and x degrees$

Find x.

Try it yourself

x + 38 = 90

Solve for x

Test yourself

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

All lessons in Angles

2Straight Lines and Supplements

5Around a Point

8Transversal Problems

11The Exterior Angle

3Right Angles and Complements

6The Angle Bisector

9Triangle Angle Sum

12Final Challenges