Area and Circumference Flashcard

Front

What does 'circumference' mean?

Back

Distance around a circle.

Front

Is the red line a radius or diameter of the circle?

Back

Radius.

Front

What is the area of a circle with a radius of 5 m? Use 3 for pi and choose the answer that is the closest.

Back

47.13 m².

Front

Find the radius of a circle whose diameter is 40 ft.

Back

20 ft.

Front

What is the radius of a circle when the diameter is 70 m?

Back

35 m.

Front

What is the formula for the circumference of a circle?

Back

C = 2πr or C = πd.

Front

What is the formula for the area of a circle?

Back

A = πr².

Front

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

Back

The area becomes four times larger.

Front

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

Back

20 cm.

Front

If the circumference of a circle is 31.4 m, what is the radius? Use 3 for pi.

Back

5 m.