radius, diameter, Circumference

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 circumference of a circle?

Back

Circumference = 2 × π × radius or Circumference = π × diameter.

Tags

CCSS.7.G.B.4

Front

What is the value of π (pi)?

Back

π (pi) is approximately 3.14.

Tags

CCSS.HSG.GMD.A.1

Front

If the radius of a circle is 3 ft, what is the diameter?

Back

Diameter = 2 × radius = 2 × 3 ft = 6 ft.

Tags

CCSS.7.G.B.4

Front

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

Back

Radius = diameter ÷ 2 = 10 ft ÷ 2 = 5 ft.

Tags

CCSS.7.G.B.4

Front

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

Back

Circumference = π × diameter.

Tags

CCSS.7.G.B.4

Front

If a circle has a radius of 4 inches, what is its circumference?

Back

Circumference = 2 × π × 4 in = 8π in ≈ 25.12 in.

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

How do you find the radius if you know the circumference?

Back

Radius = Circumference ÷ (2 × π).

Tags

CCSS.7.G.B.4