Radius and Diameter

Front

What is the radius of a circle?

Back

The radius is a straight line from the center of a circle to its circumference.

Front

What is the diameter of a circle?

Back

The diameter is a straight line that passes through the center of the circle and touches two points on its circumference.

Front

If the radius of a circle is 4 mm, what is the diameter?

Back

The diameter is 8 mm (Diameter = 2 x Radius).

Front

If the diameter of a circle is 10 in, what is the radius?

Back

The radius is 5 in (Radius = Diameter / 2).

Front

What is the relationship between radius and diameter?

Back

The diameter is twice the length of the radius.

Front

What is the circumference of a circle?

Back

The circumference is the distance around the circle, calculated as C = 2πr, where r is the radius.

Front

What is the area of a circle?

Back

The area is the space contained within the circle, calculated as A = πr².

Front

If the radius of a circle is 6 m, what is the area?

Back

The area is 36π m² (Area = π x 6²).

Front

If the diameter of a circle is 12 cm, what is the circumference?

Back

The circumference is 12π cm (Circumference = π x Diameter).

Front

What is the formula to find the radius from the area of a circle?

Back

Radius = √(Area/π).