Area of Circles

Front

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

Back

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

Front

What does 'radius' mean in relation to a circle?

Back

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

Front

What is 'π' (pi)?

Back

π (pi) is a constant approximately equal to 3.14, used in calculations involving circles.

Front

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

Back

Area = π × (5 cm)² = 78.5 cm².

Front

What is the diameter of a circle?

Back

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

Front

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

Back

Use the formula: r = √(Area/π).

Front

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

Back

Area = π × (10 m)² = 314.16 m².

Front

What is the relationship between diameter and radius?

Back

The diameter is equal to 2 times the radius (d = 2r).

Front

If a circle has an area of 50.27 m², what is its radius?

Back

Radius = √(50.27/π) ≈ 4.0 m.

Front

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

Back

Area = π × (3 cm)² ≈ 28.27 cm².