Circles

Front

Circles with exactly the same radius measures

Back

Congruent Circles

Front

Half a circle or an arc that is 180 degrees

Back

Semicircle

Front

What is the perimeter of a circle with a radius of 10?

Back

20π

Front

What is the area of a circle with a radius of 5?

Back

25π

Front

What do you call a line that touches a circle at exactly one point?

Back

Tangent Line

Front

What is the formula for the circumference of a circle?

Back

C = 2πr

Front

What is the formula for the area of a circle?

Back

A = πr²

Front

What is a chord in a circle?

Back

A line segment whose endpoints lie on the circle.

Front

What is the central angle of a circle?

Back

An angle whose vertex is at the center of the circle.

Front

What is an arc in a circle?

Back

A part of the circumference of a circle.