Area of a Circle

Front

What is the formula for the area of a circle?

Back

Area = π × r², where r is the radius.

Front

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

Back

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

Front

What does the term 'diameter' mean in relation to 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 5 cm, what is its area?

Back

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

Front

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

Back

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

Front

What is the approximate value of π (pi)?

Back

π (pi) is approximately 3.14.

Front

How do you convert diameter to radius?

Back

Divide the diameter by 2.

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 length of the radius.

Front

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

Back

Radius = √(Area/π) = √(50) cm ≈ 7.07 cm.