Parts of a Circle
Area
Circumference
Semi-Circles
Real World Application / Challenge
100
Which color represents the diameter?
Blue
100
Find the area of the circle.
Leave your answer in terms of pi.
100
A circle with its dimensions, in feet (ft), is shown.
What is the circumference, in feet, of the circle? Round to the nearest tenth.
4.7 feet
100
Find the area of the semi-circle. Use 22/ 7 for pi. Round to the nearest hundredth, if necessary.
616 in2
100
The Ferris wheel shown makes 12 revolutions per ride.
How far would someone travel during one ride? Round to the nearest foot.
A rider would travel about 2,375 feet per ride.
200
Which color represents the radius?
Green
200
A circle with its dimensions, in yards, is shown.
What is the area, in square yards, of half of the circle? Use 3.14 for pi. Round to the nearest tenth.
36.19 yd2
200
Find the circumference of the circle.
43.96 yd
200
A watermelon slice has a diameter of 20 cm. Use 3.14 for pi.
What is the area of the face of the watermelon slice? Round to the nearest hundredth.
157.08 cm2
200
A bug was sitting on the tip of a wind turbine blade that was 24 inches long when it started to rotate. The bug held on for 5 rotations before flying away.
How far did the bug travel before it flew off? Round to the nearest inch.
The bug traveled about 754 inches before it flew off.
300
Which color represents the circumference?
Red
300
A hubcap has a radius of 16 centimeters.
What is the area of the hubcap? Round your answer to the nearest hundredth. Use 22/7 for pi.
The area of the hubcap is about 804.25 cm2
300
Find the circumference of each circle. Round to the nearest tenth.
73.5 in
300
Ken’s landscape gardening business creates odd-shaped lawns that include semicircles.
Find the perimeter of this semicircular section of the lawn in this design. Use 3.14 for pi. Round to the nearest meter.
The perimeter of the lawn is about 31 meters.
300
The diameter of a bike wheel is 27 inches.
If the wheel makes 15 complete rotations, how far does the bike travel? Use 3.14 for pi.
The bike travels about 1271.7 inches in 15 complete rotations.
400
Identify the length of the radius and diameter.
Radius =
Diameter =
Radius = 12 mi
Diameter = 24 mi
400
What is the area? Use 3.14 for pi. Round to the nearest tenths.
149.6 mi²
400
Find the circumference of the watch face. Use 22/7 for pi.
88 mm
400
A stained glass window is shaped like a semicircle. The bottom edge of the window is 36 inches long.
What is the area of the stained glass window? Round your answer to the nearest hundredth.
approximately
508.94 in2
400
The circumference of Rachel's hula hoop is 72 inches.
What is the diameter of the hula hoop? Round to the nearest inch. Use 3.14 for pi.
The diameter is approximately 23 inches.
500
Identify the length of the radius and diameter.
Radius =
Diameter =
Radius = 8 mi
Diameter = 16 mi
500
What is the area? Use 3.14 for pi. Round to the nearest tenths.
30.2 cm2
500
Find the circumference of the plate. Use 22/7 for pi. Round to the nearest hundredth.
28.29 in
500
You and your friends have just eaten half of a pizza. You notice that the radius measures 6 in.
What is the area of the remaining pizza? Round to the nearest hundredth.
56.55 in2
500
A circle’s circumference is approximately 44 cm.
Complete each statement.
The circle’s diameter is approximately ___ cm.
The circle’s radius is approximately ___ cm.
The circle’s area is approximately ___ cm2.
The circle’s diameter is approximately 14 cm.
The circle’s radius is approximately 7 cm.
The circle’s area is approximately 154 cm2.