Perimeter and Area of Semicircles

This video tutorial explains how to calculate the perimeter of a semicircle given its radius. It begins with an introduction to semicircles and their radii, followed by an explanation of the circle's circumference formula. The video then details the steps to calculate the perimeter of a semicircle, using both the radius and the area of the semicircle. Two example problems are solved to demonstrate the calculation process, showing how to derive the perimeter from both the radius and the area.

What is the definition of a semicircle?

• A triangle

• A full circle

• Half of a circle

• A quarter of a circle

How is the circumference of a semicircle calculated?

• r/2

• πr/2

• πr

• 2πr

What additional component is added to half the circumference to find the perimeter of a semicircle?

• Radius

• Diameter

• Area

• Volume

What is the formula for the perimeter of a semicircle?

• 2πr

• r + πr

• r/2 + πr

• 2r + πr

If the radius of a semicircle is 8 inches, what is the approximate perimeter?

• 50.2 inches

• 30.5 inches

• 41.1 inches

• 25.1 inches

What is the first step in calculating the radius from the area of a semicircle?

• Divide the area by π

• Divide the area by 0.5

• Multiply the area by π

• Multiply the area by 0.5

What is the formula for the area of a semicircle?

• πr^2

• 0.5πr^2

• 2πr^2

• πr

How do you find the radius from the area of a semicircle?

• Divide the area by 0.5π and then take the square root

• Take the square root of the area

• Multiply the area by 0.5π and then take the square root

• Multiply the area by π

What is the radius if the area of a semicircle is 100.531 square centimeters?

• 12 cm

• 10 cm

• 8 cm

• 6 cm

What is the perimeter of a semicircle with a radius of 8 cm?

• 41.1 cm

• 50.1 cm

• 20.1 cm

• 30.1 cm