Identify the Parts of a Circle

Front

What is the radius of a circle?

Back

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

Front

What is the diameter of a circle?

Back

The diameter is the distance across the circle through its center, equal to twice the radius.

Tags

CCSS.HSG.C.A.2

Front

How do you calculate the radius from the diameter?

Back

Radius = Diameter / 2.

Tags

CCSS.7.G.B.4

Front

What is the formula for the circumference of a circle given the radius?

Back

C = 2πr.

Tags

CCSS.7.G.B.4

Front

What is the formula for the circumference of a circle given the diameter?

Back

C = πd.

Tags

CCSS.7.G.B.4

Front

If the radius of a circle is 9.5 mm, what is the diameter?

Back

Diameter = 2 * Radius = 2 * 9.5 mm = 19 mm.

Tags

CCSS.7.G.B.4

Front

If a circular swimming pool has a diameter of 21 feet, what is its radius?

Back

Radius = Diameter / 2 = 21 ft / 2 = 10.5 ft.

Tags

CCSS.7.G.B.4

Front

What is the relationship between radius and diameter?

Back

The diameter is always twice the length of the radius.

Tags

CCSS.7.G.B.4

Front

What is π (pi)?

Back

π (pi) is a mathematical constant approximately equal to 3.14, representing the ratio of the circumference of a circle to its diameter.

Tags

CCSS.HSG.GMD.A.1

Front

What is the area of a circle formula?

Back

Area = πr².

Tags

CCSS.7.G.B.4