Circles, Circles, Circles

Front

What is the formula for finding the area of a circle?

Back

A = π·r²

Front

What is the formula for finding the circumference of a circle?

Back

C = 2·π·r

Front

What is the distance from the center to any point on the circle called?

Back

Radius

Front

What is the diameter of a circle?

Back

The distance across the circle through the center, equal to twice the radius.

Front

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

Back

A = π·(5)² = 78.54 square inches.

Front

If the circumference of a circle is 31.4 inches, what is the radius?

Back

Radius = 31.4 / (2·π) = 5 inches.

Front

What is π (pi)?

Back

A mathematical constant approximately equal to 3.14, representing the ratio of a circle's circumference to its diameter.

Front

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

Back

Diameter = 2 × Radius.

Front

What is the relationship between diameter and circumference?

Back

Circumference = π × Diameter.

Front

If a circle has an area of 50.24 square inches, what is the radius?

Back

Radius = √(50.24/π) ≈ 4 inches.