Radius and Diameter

Front

What is the definition of a radius?

Back

A radius is a line segment from the center of a circle to any point on its circumference.

Front

What is the definition of a diameter?

Back

A diameter is a line segment that passes through the center of a circle and has its endpoints on the circle.

Front

How is the diameter related to the radius?

Back

The diameter is twice the length of the radius.

Front

What is the formula for calculating the circumference of a circle?

Back

Circumference = 2 × π × radius.

Front

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

Back

Diameter = 2 × radius = 2 × 4 m = 8 m.

Front

What does 'circumference' refer to in a circle?

Back

Circumference refers to the distance around a circle.

Front

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

Back

Radius = Diameter ÷ 2 = 10 m ÷ 2 = 5 m.

Front

What is the relationship between radius and circumference?

Back

The circumference of a circle increases as the radius increases.

Front

What is the area of a circle with a radius of 3 m?

Back

Area = π × radius² = π × (3 m)² = 9π m².

Front

What is the term for the longest chord in a circle?

Back

The longest chord in a circle is the diameter.