Area and Circumference of Circles

Front

What is the formula for finding the area of a circle?

Back

A = π·r²

Tags

CCSS.7.G.B.4

Front

What is the relationship between the radius and diameter of a circle?

Back

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

Front

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

Back

10 inches

Tags

CCSS.7.G.B.4

Front

What is the formula for finding the circumference of a circle?

Back

C = π·d or C = 2·π·r

Tags

CCSS.7.G.B.4

Front

If the diameter of a circle is 12 feet, what is the radius?

Back

6 feet

Tags

CCSS.7.G.B.4

Front

What is the area of a circle with a radius of 7 meters?

Back

A = π·(7)² = 49π ≈ 153.94 m²

Tags

CCSS.7.G.B.4

Front

How do you convert diameter to radius?

Back

Divide the diameter by 2.

Tags

CCSS.7.G.B.4

Front

What is the circumference of a circle with a radius of 4 cm?

Back

C = 2·π·4 = 8π ≈ 25.13 cm

Tags

CCSS.7.G.B.4

Front

If the area of a circle is 78.54 m², what is the radius?

Back

r = √(A/π) = √(78.54/π) ≈ 5 m

Tags

CCSS.7.G.B.4

Front

What is the area of a circle with a diameter of 10 inches?

Back

A = π·(5)² = 25π ≈ 78.54 in²

Tags

CCSS.7.G.B.4