How do you find the radius if you are given the diameter?
Diameter divided by 2 gives you the radius.
Define circumference
The distance around a circle.
Find the approximate Area of a circle when
Radius = 4 units
Area = 50.24 square units
What is the longest chord on a circle?
The diameter.
What is the ratio for finding pi?
Circumference divided by its diameter or
C/d
What is the radius of a circle if the diameter is 19 ft.
Radius = 9.5 ft.
Find the approximate circumference:
When radius = 5 ft.
31.4 ft.
Find the approximate Area of a circle
when diameter = 14 ft.
area = 153.86 sq. ft.
Jimmy is going to run 4 times around the circular lake. If the lake has a diameter of 12 meters, what would be the distance he runs around the lake?
150.72 meters
If the following Semi-circle has a diameter of 16 yd, what is the area?

100.48 sq. yd.
What is the diameter of a circle if the radius is 19.4 yd.
diameter = 38.8 yd.
Find the approximate Circumference
when diameter = 21 in.
circumference = 65.94 in.
Find the approximate Area of a circle when the diameter = 4.2 mi. Round to the nearest hundredth.
Area = 13.85 sq. mi.
Which pizza provides a better deal? Why?
The large 16-inch diameter pizza for $12.99 or the $26 X-Large with a radius of 12 in.
The $26 X-Large pizza is a better deal.
(The large pizza is about $0.064 per square inch)
(The X-Large pizza is about $0.058 per square inch)
How is finding an exact area different from finding an approximate area?
Exact keeps pi in the answer.
What is the radius of a circle if the diameter is 16.5 mi
Radius = 8.25 mi
Jenn will be walking around the circular running track 2 times. What is the distance she will travel if the radius of the track is 12 meters?
150.72 meters
Find the approximate Area of the following shape:
Area = 28.26 sq. cm
A circular silver tray has a diameter of 28 centimeters and a circumference is 87.92 cm. How would you find pi?
87.92 divided by 28

The inner circle has a radius of 9 in. The outer circle has a diameter of 24 in. Determine the approximate area of the shaded region.
About 197.82 square inches.
If the radius is
2 3/5
What is the diameter?
5.2 or
5 1/5
Find the approximate diameter when the Circumference is 69.08 m
Diameter = 22 m
Find the approximate Area of a circle when the circumference is about 37.68
Area = 113.04 (radius is 6)

Determine the distance the runners run around the edge of the track. Round to the nearest whole number
1,320 feet
(Outer rectangle is 1000 ft, and 2 semi circles that are about 160.14 ft each or 320.28 ft total)
Jackie will be painting a mural of a basketball in the gym. What area will she be painting if the basketball will have a diameter of 18 yards?
254.34 yards2