Circumference of a Circle

Front

What is the formula for the circumference of a circle?

Back

C = πd or C = 2πr, where C is circumference, d is diameter, r is radius, and π (pi) is approximately 3.14.

Tags

CCSS.7.G.B.4

Front

What is the relationship between diameter and radius?

Back

The diameter is twice the radius. d = 2r.

Tags

CCSS.7.G.B.4

Front

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

Back

The diameter is 19 mm (d = 2r).

Tags

CCSS.7.G.B.4

Front

How do you calculate the circumference of a circle with a diameter of 14 cm?

Back

Use the formula C = πd. C = 3.14 * 14 = 43.96 cm.

Tags

CCSS.7.G.B.4

Front

What is the circumference of a circle with a radius of 5 inches?

Back

C = 2πr = 2 * 3.14 * 5 = 31.4 inches.

Tags

CCSS.7.G.B.4

Front

What does 'rounding to 1 decimal place' mean?

Back

It means to adjust a number to one digit after the decimal point.

Tags

CCSS.5.NBT.A.4

Front

If a circle has a circumference of 78.5 cm, what is its diameter?

Back

Use the formula d = C/π. d = 78.5 / 3.14 = 25 cm.

Tags

CCSS.7.G.B.4

Front

What is the circumference of a circle with a diameter of 3.5 feet?

Back

C = πd = 3.14 * 3.5 = 10.99 feet.

Tags

CCSS.7.G.B.4

Front

What is the value of π (pi) used in calculations?

Back

π (pi) is approximately 3.14.

Tags

CCSS.HSG.GMD.A.1

Front

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

Back

Use the formula r = C/(2π).

Tags

CCSS.7.G.B.4