Area of a circle

Front

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

Back

Area = π × r², where r is the radius.

Front

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

Back

Radius = 5 cm.

Front

What is the value of π (pi) approximately?

Back

π ≈ 3.14.

Front

How do you convert diameter to radius?

Back

Radius = Diameter ÷ 2.

Front

What is the area of a circle with a radius of 4 cm?

Back

Area = π × (4 cm)² = 50.24 cm².

Front

What is the circumference of a circle?

Back

Circumference = 2 × π × r.

Front

If a circle has a radius of 7 m, what is its area?

Back

Area = π × (7 m)² ≈ 153.94 m².

Front

What does the term 'diameter' refer to in a circle?

Back

Diameter is the distance across the circle through its center.

Front

What is the relationship between diameter and radius?

Back

Diameter = 2 × Radius.

Front

If the area of a circle is 78.5 cm², what is the radius?

Back

Radius ≈ 5 cm.