Circles: Area and Circumference Review

Front

What is the formula for the circumference of a circle?

Back

Circumference = 2 x Pi x Radius

Front

What is the diameter of a circle?

Back

The diameter is twice the radius of the circle.

Front

If the radius of a circle is 8 cm, what is the diameter?

Back

16 cm

Front

If the radius of a circle is 10 cm, what is the circumference?

Back

Circumference = 2 x Pi x 10 = 62.83 cm (approximately)

Front

If the circumference of a circle is 50.24 cm, what is the radius?

Back

Radius = Circumference / (2 x Pi) = 50.24 / (2 x 3.14) = 8 cm (approximately)

Front

What is the formula for the area of a circle?

Back

Area = Pi x Radius^2

Front

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

Back

Area = Pi x 5^2 = 78.54 cm^2 (approximately)

Front

What is the relationship between radius and diameter?

Back

Diameter = 2 x Radius

Front

If the diameter of a circle is 16 cm, what is the radius?

Back

Radius = Diameter / 2 = 8 cm

Front

What is Pi (π)?

Back

Pi (π) is a constant approximately equal to 3.14, representing the ratio of the circumference of a circle to its diameter.