Circle Geometry Flashcard

Front

What is the formula for the circumference of a circle?

Back

C = πd or C = 2πr

Front

If the radius of a circle is 7 meters, what is the circumference? Use 3.14 for π.

Back

C = 2πr = 2 * 3.14 * 7 = 43.96 meters

Front

What is the diameter of a circle if the radius is 12 meters?

Back

Diameter = 2 * radius = 2 * 12 = 24 meters

Front

The __________ is the longest chord in a circle.

Back

diameter

Front

What is the area of a circle with a radius of 5 meters? Use 3.14 for π.

Back

A = πr² = 3.14 * 5² = 78.5 square meters

Front

If the circumference of a circle is 31.4 meters, what is the radius? Use 3.14 for π.

Back

C = 2πr; 31.4 = 2 * 3.14 * r; r = 5 meters

Front

What is the relationship between the radius and diameter of a circle?

Back

The diameter is twice the radius.

Front

What do you call a line segment that connects two points on a circle?

Back

chord

Front

If a circle has a diameter of 10 meters, what is its radius?

Back

Radius = diameter / 2 = 10 / 2 = 5 meters

Front

What is the area of a circle with a diameter of 8 meters? Use 3.14 for π.

Back

A = πr²; r = 4; A = 3.14 * 4² = 50.24 square meters