circumference and Area of a Circle

Front

What is the definition of the diameter of a circle?

Back

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

Tags

CCSS.HSG.C.A.2

Front

What is the definition of the radius of a circle?

Back

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

Front

What is the formula for the circumference of a circle?

Back

C = 2πr, where C is the circumference and r is the radius.

Tags

CCSS.7.G.B.4

Front

If the radius of a circle is 7 meters, what is the circumference?

Back

C = 2π(7) = 43.98 meters.

Tags

CCSS.7.G.B.4

Front

What is the formula for the area of a circle?

Back

A = πr², where A is the area and r is the radius.

Tags

CCSS.7.G.B.4

Front

If the radius of a circle is 5 inches, what is the area?

Back

A = π(5)² = 78.54 square inches.

Tags

CCSS.7.G.B.4

Front

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

Back

The radius is half of the diameter. r = d/2.

Tags

CCSS.7.G.B.4

Front

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

Back

r = 10 cm / 2 = 5 cm.

Tags

CCSS.7.G.B.4

Front

What is the relationship between diameter and circumference?

Back

The circumference is π times the diameter. C = πd.

Tags

CCSS.7.G.B.4

Front

If the circumference of a circle is 31.4 cm, what is the diameter?

Back

d = C/π = 31.4 cm / π = 10 cm.

Tags

CCSS.7.G.B.4