Radius and Diameter

Front

What is the definition of a radius in a circle?

Back

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

Front

What is the definition of a diameter in a circle?

Back

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

Front

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

Back

20 m

Front

If the diameter of a circle is 50 m, what is the radius?

Back

25 m

Front

What is the relationship between radius and diameter?

Back

The diameter is always twice the length of the radius.

Front

Is a radius always half of the diameter?

Back

Yes, the radius is always half of the diameter.

Front

If a circle has a radius of 15 cm, what is the circumference? (Use π ≈ 3.14)

Back

Circumference = 2 × π × radius = 2 × 3.14 × 15 = 94.2 cm.

Front

What is the formula to calculate the area of a circle using the radius?

Back

Area = π × radius².

Front

If the diameter of a circle is 80 m, what is the radius?

Back

40 m

Front

What is the diameter of a circle with a radius of 12 m?

Back

24 m