Circumference and Area of a Circle

Front

What is the formula for the circumference of a circle?

Back

Circumference = 2 × π × r (where r is the radius) or Circumference = π × d (where d is the diameter).

Front

What is the formula for the area of a circle?

Back

Area = π × r² (where r is the radius).

Front

If a circle has a radius of 7 cm, what is its circumference?

Back

43.96 cm.

Front

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

Back

31.4 cm.

Front

What is the radius of a circle?

Back

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

Front

What is the diameter of a circle?

Back

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

Front

What is a chord in a circle?

Back

A chord is a line segment whose endpoints lie on the circle.

Front

What is the center of a circle?

Back

The center is the point that is equidistant from all points on the circumference.

Front

If you want to find the area of a circular lawn, what do you need to calculate?

Back

You need to calculate the area.

Front

What is π (pi)?

Back

π (pi) is a mathematical constant approximately equal to 3.14, used in calculations involving circles.