Circles: Areas and Circumference

How do you find the area of a circle?

A _____ is half of a circle.

• circumference

• pi

• semicircle

• composite figure

What is the perimeter of the semi-circle? Round to the nearest hundredth. Don't forget to label.

Sadie has 38 inches of fringe to sew around a circular pillow. What is the diameter of the largest pillow she can use? Round to the nearest hundredth. Don't forget to label.

A circular table top has an area of 324 square inches. Which measurement is closest to the radius of the table top in inches? Round to the nearest hundredth. Don't forget to label.

The area of a circle is 12.56 yd². What is the circle's diameter? Round to the nearest whole number.

What is the diameter of a circle if its area is 360 in² . Round to the nearest hundredth. Don't forget to label.

What is the circumference of a circle with a diameter of 1 inch? Use 3.14 for pi.

• 3.14 inches

• 6.28 inches

• 314 inches

• 628 inches

The perimeter of a circle is usually called the...

• radius

• diameter

• circumference

• area

The area of the circle would be found using which of the following formulas...  (9 cm is the radius)

• Area = π(4.5)²

• Area = π(9)²

• Area = π(18)²

• None of these