Area of a Circle

Front

What is the formula for the area of a circle?

Back

Area = π × r², where r is the radius of the circle.

Front

What is the value of π (pi) approximately?

Back

π is approximately 3.14.

Front

If the radius of a circle is doubled, how does the area change?

Back

The area increases by a factor of four.

Front

What is the relationship between diameter and radius?

Back

Diameter = 2 × Radius.

Front

How do you find the radius if you know the area of a circle?

Back

Radius = √(Area/π).

Front

What is the area of a circle with a radius of 5 cm?

Back

Area = π × (5 cm)² = 78.54 cm².

Front

What is the area of a circle with a diameter of 10 m?

Back

Area = π × (5 m)² = 78.54 m².

Front

How do you convert diameter to radius?

Back

Radius = Diameter / 2.

Front

What is the area of a circle with a radius of 10 inches?

Back

Area = π × (10 inches)² = 314.16 in².

Front

If a circle has an area of 50 cm², what is its radius?

Back

Radius = √(50 cm²/π) ≈ 3.99 cm.