Calculating Areas of Circles

This video tutorial explains how to calculate the area of semicircles and quarter circles. It begins with an introduction to the concepts of semicircles and quarter circles, emphasizing that a semicircle is half of a full circle and a quarter circle is one-fourth. The video then provides step-by-step instructions for calculating the area of each, using the formula for the area of a circle (πr²) and adjusting it by dividing by 2 for semicircles and by 4 for quarter circles. The tutorial includes examples with specific measurements to illustrate the calculations. The video concludes by highlighting the importance of understanding these concepts and remembering the division step in the calculations.

What fraction of a full circle does a semi circle represent?

• 1/2

• 1/3

• 1/4

• 1/5

What fraction of a full circle does a quarter circle represent?

• 1/5

• 1/4

• 1/3

• 1/2

What is the formula for the area of a semi circle?

• 2πr

• πr²/2

• πd

• πr²

If the diameter of a circle is 8, what is the radius?

• 5

• 2

• 3

• 4

How do you calculate the area of a semi circle with a radius of 4?

• 8π/2

• 16π/2

• 8π

• 16π

What is the area of a semi circle with a radius of 4 using π = 3.14?

• 31.4

• 25.12

• 50.24

• 12.56

What is the formula for the area of a quarter circle?

• πr²

• πd

• 2πr

• πr²/4

If the radius of a circle is 6, what is the diameter?

• 3

• 12

• 6

• 9

How do you calculate the area of a quarter circle with a radius of 6?

• 36π/4

• 18π

• 18π/4

• 36π

What is the area of a quarter circle with a radius of 6 using π = 3.14?

• 14.13

• 28.26

• 56.52

• 113.04