Area of Circles

Front

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

Back

Area = π × r², where r is the radius.

Front

What is the radius of a circle?

Back

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

Front

What is the diameter of a circle?

Back

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

Front

How do you find the area of a semicircle?

Back

Area of a semicircle = (π × r²) / 2.

Front

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

Back

Area = π × (5 cm)² = 25π cm² ≈ 78.54 cm².

Front

What does 'area' mean in geometry?

Back

Area refers to the amount of space inside a shape.

Front

If a circle has a diameter of 10 inches, what is its radius?

Back

Radius = Diameter / 2 = 10 inches / 2 = 5 inches.

Front

What is the area of a circle with a radius of 7 cm?

Back

Area = π × (7 cm)² = 49π cm² ≈ 153.94 cm².

Front

What is the relationship between radius and diameter?

Back

The diameter is twice the radius (Diameter = 2 × Radius).

Front

How do you convert diameter to radius?

Back

Radius = Diameter / 2.