Area of Circles and Composite Figures

Front

What is the formula for the area of a circle?

Back

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

Front

What is the value of π (pi) approximately?

Back

π is approximately 3.14.

Front

How do you find the radius of a circle if you know the diameter?

Back

Radius = Diameter / 2.

Front

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

Back

Area = π(7)² ≈ 153.94 cm².

Front

What is a composite figure?

Back

A composite figure is a shape that is made up of two or more simple shapes.

Front

How do you find the area of a composite figure?

Back

Find the area of each simple shape and then add them together.

Front

What is the area of a triangle?

Back

Area = 1/2 × base × height.

Front

What is the area of a triangle with a base of 10 cm and a height of 5 cm?

Back

Area = 1/2 × 10 × 5 = 25 cm².

Front

What is the difference between diameter and radius?

Back

Diameter is twice the radius; it is the distance across the circle through the center.

Front

If the area of a circle is 254.34 cm², what is the radius?

Back

Radius = √(Area/π) ≈ 9 cm.