Area and circumference of circles

Front

What is the definition of a radius in a circle?

Back

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

Front

What is the definition of a diameter in 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

If the radius of a circle is 5 cm, what is the diameter?

Back

10 cm

Tags

CCSS.7.G.B.4

Front

What is the formula for the circumference of a circle?

Back

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

Tags

CCSS.7.G.B.4

Front

If the diameter of a circle is 12 inches, what is the circumference? (Use π = 3.14)

Back

Circumference = 3.14 × 12 = 37.68 inches.

Tags

CCSS.7.G.B.4

Front

What is the formula for the area of a circle?

Back

Area = π × radius².

Tags

CCSS.7.G.B.4

Front

If the radius of a circle is 7 m, what is the area? (Use π = 3.14)

Back

Area = 3.14 × 7² = 153.86 m².

Tags

CCSS.7.G.B.4

Front

What is the area of a semicircle with a radius of 4 cm? (Use π = 3.14)

Back

Area = (1/2) × π × 4² = 25.12 cm².

Tags

CCSS.7.G.B.4

Front

How do you find the area of a square that is not covered by a circle?

Back

Subtract the area of the circle from the area of the square.

Tags

CCSS.3.MD.C.7B

CCSS.4.MD.A.3

Front

If a square has a side length of 10 inches, what is its area?

Back

Area = 10 × 10 = 100 in².

Tags

CCSS.3.MD.C.7B

CCSS.4.MD.A.3