What Is a Right Angle?

What Is a Right Angle?

A right angle is an angle of 90°.

A right angle is a quarter of a revolution.

right angle

Note: Right angles are often denoted by adding a small right angle that forms a square with the angle.

Dictionary Definition

The Oxford English Dictionary defines a right angle as "an angle of ninety degrees; specifically one formed by two perpendicular lines, as in the corner of a square."

Real Examples of Right Angles

The angles below are all right angles:

examples of right angles. square in angle and 90 degrees

A Real Example of a Right Angle: The Right Triangle

A right triangle is a triangle containing a right angle.

right angle in a right triangle

The right triangle is one of the most useful triangles in mathematics.

It is used for Pythagoras' theorem and in trigonometry.

Read more about right triangles

See Also

What is a right triangle? Who was Euclid? What are complementary angles?