Perimeter/Area of Circles and SemiCircles

Front

What is the formula for the circumference of a circle?

Back

C = πd or C = 2πr

Tags

CCSS.7.G.B.4

Front

How do you calculate the circumference of a circle with a radius of 5 inches?

Back

C = 2π(5) = 31.42 inches

Tags

CCSS.7.G.B.4

Front

What is the relationship between diameter and radius?

Back

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

Tags

CCSS.7.G.B.4

Front

What is the formula for the area of a circle?

Back

A = πr²

Tags

CCSS.7.G.B.4

Front

How do you find the area of a circle with a radius of 10 cm?

Back

A = π(10)² = 314.16 cm²

Tags

CCSS.7.G.B.4

Front

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

Back

A = π(7)² = 153.94 in²

Tags

CCSS.7.G.B.4

Front

How do you calculate the area of a semicircle?

Back

A = (1/2)πr²

Tags

CCSS.7.G.B.4

Front

What is the area of a semicircle with a diameter of 18 cm?

Back

A = (1/2)π(9)² = 127.17 cm²

Tags

CCSS.7.G.B.4

Front

What is the circumference of a circle with a diameter of 10 cm?

Back

C = π(10) = 31.42 cm

Tags

CCSS.7.G.B.4

Front

If the radius of a circle is doubled, how does the area change?

Back

The area increases by a factor of 4.

Tags

CCSS.7.G.B.4