Parts of a Circle

Front

The distance all the way across the circle, but through the center, is called the...

Back

Diameter

Front

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

Back

6 units

Front

Is the red line a radius or diameter of the circle?

Back

Diameter

Front

What is the radius?

Back

18

Front

What is the diameter?

Back

18

Front

The distance from the center of the circle to any point on its circumference is called the...

Back

Radius

Front

What is the formula to find the circumference of a circle?

Back

C = πd or C = 2πr

Front

If the radius of a circle is 10 units, what is the diameter?

Back

20 units

Front

What is the relationship between diameter and radius?

Back

Diameter is twice the radius (d = 2r).

Front

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

Back

A = πr² = 25π square units.