Sponge - Radius, Diameter, Circumference

Front

What is the definition of Radius?

Back

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

Front

What is the definition of Diameter?

Back

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

Front

How do you calculate the Circumference of a circle?

Back

Circumference = 2 × π × radius or Circumference = π × diameter.

Front

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

Back

Diameter = 2 × radius = 2 × 5 cm = 10 cm.

Front

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

Back

Radius = diameter ÷ 2 = 20 cm ÷ 2 = 10 cm.

Front

What is the relationship between Radius and Diameter?

Back

The diameter is always twice the length of the radius.

Front

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

Back

Circumference = 2 × π × 7 inches ≈ 43.98 inches.

Front

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

Back

Area = π × radius².

Front

If the radius of a circle is 3 m, what is the area?

Back

Area = π × (3 m)² ≈ 28.27 m².

Front

What is the circumference of a circle with a diameter of 12 ft?

Back

Circumference = π × 12 ft ≈ 37.70 ft.