Intro to Circles

Front

What is a circle?

Back

A circle is a shape consisting of all points in a plane that are at a given distance from a fixed point, called the center.

Front

What is the center of a circle?

Back

The center of a circle is the fixed point from which all points on the circle are equidistant.

Front

What is the radius of a circle?

Back

The radius is the distance from the center of the circle to any point on the circle.

Front

What is the diameter of a circle?

Back

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

Front

How do you calculate the circumference of a circle?

Back

Circumference can be calculated using the formula C = πd, where d is the diameter.

Front

What is the value of π (pi)?

Back

π (pi) is approximately 3.14.

Front

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

Back

The diameter is 10 cm (diameter = 2 x radius).

Front

If the diameter of a circle is 20 cm, what is the radius?

Back

The radius is 10 cm (radius = diameter / 2).

Front

What is the formula for the circumference of a circle using the radius?

Back

C = 2πr, where r is the radius.

Front

What is the area of a circle?

Back

The area of a circle is calculated using the formula A = πr².