Area and Circumference of a Circle

Front

What does C represent in the formula C = π·d?

Back

Circumference

Front

Estimate the circumference of a circle with a radius of 12.5 mm using 3 for pi.

Back

78.5 mm

Front

What is the area of a circle whose diameter is 22?

Back

379.94

Front

What is the circumference of a circle with a diameter of 12 cm?

Back

37.68 cm

Front

Which is the closest area of a circle with a radius of 10?

Back

314

Front

What is the formula for the circumference of a circle?

Back

C = π·d or C = 2·π·r

Front

What is the formula for the area of a circle?

Back

A = π·r²

Front

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

Back

The area increases by a factor of four.

Front

What is the value of π (pi) approximately?

Back

3.14

Front

How do you find the diameter of a circle if you know the circumference?

Back

d = C/π