Area of a Circle

Front

What is the formula for the area of a circle given the radius?

Back

A = πr²

Front

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

Back

A = π(3)² = 28.26 cm²

Front

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

Back

A = π(7)² ≈ 153.86 cm²

Front

A line that goes from one edge of the circle to another and crosses the center is the __________.

Back

Diameter

Front

What is the area of a circle with a radius of 9 in?

Back

A = π(9)² ≈ 254.34 in²

Front

What is the value of π (pi) approximately?

Back

π ≈ 3.14

Front

What is the relationship between diameter and radius?

Back

Diameter = 2 × Radius

Front

What is the circumference of a circle?

Back

Circumference = 2πr or πd

Front

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

Back

The area increases by a factor of 4.

Front

What is the radius of a circle with an area of 50 cm²?

Back

Radius = √(Area/π) ≈ 3.99 cm