Area & Circumference of Circles

Front

What is the formula for the area of a circle?

Back

Front

What is the formula for the circumference of a circle?

Back

The circumference (C) of a circle is calculated using the formula: C = 2 imes ext{pi} imes r, where r is the radius.

Front

What is the relationship between diameter and radius?

Back

The diameter (d) of a circle is twice the radius (r): d = 2r.

Front

How do you find the radius if you know the diameter?

Back

Front

What is the value of pi (π) approximately?

Back

Pi (π) is approximately equal to 3.14.

Front

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

Back

Front

If a circle has a diameter of 10 cm, what is its circumference?

Back

The circumference is C = 2 imes ext{pi} imes 5 = 31.4 ext{ cm}.

Front

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

Back

The diameter is d = 2 imes 7 = 14 inches.

Front

How far does a wheel with a diameter of 12 inches travel in one rotation?

Back

The distance traveled is equal to the circumference: C = 12 imes ext{pi} = 37.68 inches.

Front

What is the area of a circle with a radius of 3 inches?

Back