Circle Vocabulary and Measures of Arcs, Angles

Front

What is the measure of arc AXB?

Back

100 degrees

Front

Name a minor arc.

Back

AB

Front

What is the distance from the center of a circle to the boundary of a circle?

Back

Radius

Front

If the diameter of a circle is 12 meters, what is the length of the radius?

Back

6 meters

Front

What is a semi-circle?

Back

When the distance from one point to the next on the circle is exactly 180 degrees (half of a circle).

Front

What is a chord in a circle?

Back

A line segment with both endpoints on the circle.

Front

Define a major arc.

Back

An arc that measures more than 180 degrees.

Front

What is a central angle?

Back

An angle whose vertex is at the center of the circle and whose sides are radii.

Front

What is the formula for the circumference of a circle?

Back

C = πd or C = 2πr, where d is the diameter and r is the radius.

Front

What is the relationship between the radius and diameter?

Back

The diameter is twice the length of the radius.