Radius and Diameter
Circumference
Area
Circles and Beyond
Shaded Area/Misc.
100

How do you find the radius if you are given the diameter?

Diameter divided by 2 gives you the radius.

100

Define circumference

The distance around a circle.

100

Find the approximate Area of a circle when
Radius = 4

Area = 50.24

100

The olympic symbol consists of 5 circles of different colors. Without looking it up, what are the 5 colors?

Blue

Black

Red

Yellow

Green

100

What is the ratio for finding pi?

Circumference divided by its diameter or

C/d

200

What is the radius of a circle if the diameter is 19

Radius = 9.5

200

Find the approximate circumference:
When radius = 5

31.4

200

Find the approximate Area of a circle
when diameter = 14

area = 153.86

200

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

200

If the following Semi-circle has a diameter of 16, what is the area?

100.48 

300

What is the diameter of a circle if the radius is 19.4

diameter = 38.8

300

Find the approximate Circumference
when diameter = 21

circumference = 65.94

300

Find the approximate Area of a circle when the diameter = 4.2

Area = 13.8474 or 13.85

300

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)

300

The Williams family ate dinner at Olive Garden. Thetotal bill was $76. They left a tip that was 18% of the bill. How much did the Williams family pay, including the tip?

$89.68

400

What is the radius of a circle if the diameter is 16.5

Radius = 8.25

400

Find the approximate radius when the circumference is about 100.48 

Radius = 16

400

Find the approximate Area of the following shape:

Area = 28.26

400

A circular silver tray has a diameter of 28 centimeters. 

If the tray cost $136, what is the cost per square centimeter (round to the nearest cent).

About $0.22 for 1 square centimeter.

400


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.

500

If the radius is 

2 3/5

What is the diameter?

5.2 or 

5 1/5

500

Find the approximate diameter when the Circumference is 69.08

Diameter =22

500

Find the approximate Area of a circle when the circumference is about 37.68

Area = 113.04  (radius is 6)

500

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)

500

Jackie will be painting a mural of a basketball in the gym. How many square inches will she be painting if the basketball will have a diameter of 18 yards? 

254.34 yards2
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