Area of Circles

Front

What is the formula for the area of a circle?

Back

Area = πr², where r is the radius of the circle.

Front

How do you find the radius if you know the diameter?

Back

Radius = Diameter / 2.

Front

What is the value of π (pi) approximately?

Back

π is approximately 3.14.

Front

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

Back

Area = π(5)² = 25π cm² or approximately 78.54 cm².

Front

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

Back

Area = π(7)² = 49π cm² or approximately 153.94 cm².

Front

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

Back

Area = π(5)² = 25π cm² or approximately 78.54 cm².

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 4 cm?

Back

Area = π(4)² = 16π cm² or approximately 50.27 cm².

Front

If the area of a circle is 100π cm², what is the radius?

Back

Radius = √(100) = 10 cm.

Front

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

Back

Area = π(3)² = 9π cm² or approximately 28.27 cm².