Vocabulary
Circumference
Area and Circumference
Area
Finding Radius/Diameter
100

A straight line from the center to the circumference of a circle or sphere

Radius

100

What is the circumference of a circle if:

the radius = 7 yds?

43.96yds

When I need a circumference Ill just use pi d.

radius = 7 

7 * 2 = 14

14 is diameter

14 * pi is 14 pi or 43.96

100

What is the formula to find the area of a circle?



A= 

pir^2

100

What is the area of a circle if:

the Radius = 6 in

113.04 in2

6 * 6 * 3.14 

36 pi or 113.04

100

What is the diameter of a circle whose circumference is 314?

100

314 / 3.14

200

Name the line in a circle that cuts it in half.

Diameter

A diameter goes across the circle passing through the middle.

200

What is the circumference of a circle if:

the radius = 9 yds?


56.52yds

radius = 9 

9 * 2 = 18 which is the diameter

18 * pi is circumference or 18 * 3.14

18pi or 56.52


200

What day is Pi Day?

March 14.  

3/14

3.14 because the first digits of pi are 3.14

200

What is the area of a circle if:

the Radius = 3 ft

28.26 ft2

3 * 3 * 3.14

200

What is the diameter of a circle whose circumference is 690?

219.63

690 /3.14

300

The outside measurement of a circle. Or the distance around the outside of the circle

Circumference

Circumference is the perimeter of a circle.

300

What is the circumference of a circle if:

the diameter is 16.8 yards?

52.75yds

diameter = 16.8

16.8 pi

16.8 * 3.14 = 52.752

300

Find the area of a circle when the circumference is 28.26 feet.

63.59 ft2

28.26 / 3.14 = 9 This is the diameter

9/2 = 4.5 this is the radius

4.5 * 4.5 * 3.14 = 63.585

300

What is the area of a circle if:

the Diameter = 12 feet?

113.04 ft2

12/2 = 6

 6 * 6 * 3.14

300

What is the radius of a circle whose circumference is 901?

14.49

901 / 3.14 =28.98

28.98 / 2 = 14.49



400

The measurement of the inside of a circle. Or how much the circle covers

Area

400

What is the circumference of a circle if:

the radius = 7.4 yds?

46.47yds

7.4 * 2 = 14.8 which is the diameter

14.8 pi or 14.8 * 3.14 is the circumference

46.47 or 14.8π yds

400

What is the Area of a circle if the circumference is 43.96?

153.86

43.96 /3.14 = 14   Circumfence / pi is diameter

14/2 = 7       diameter / 2 is radius
7 * 7 * 3.14 = 153.86   pi r2 is area.  

153.86

400

What is the area of a circle if:

the diameter = 8 in

16π or 50.24 in2

8/2 = 4

4 * 4 * 3.14

400

What is the radius of a circle whose circumference is 372?

59.24

372 / 3.14 = 118.47

118/47 /2 = 59.24


500

Circumference divided by diameter. 

Pi - 3.14

500

The circular fountain in front of the courthouse has a radius of 9.4 feet. What is the circumference of the fountain to the nearest foot? 

59

9.4 * 2 = 18.8

18.8 * 3.14 = 59.032

Which rounds to 59.   


500

A rose garden is circular. The diameter of the garden is 18 feet. Find the total area of the garden using 3.14 for pi. 

254.34

18 /2 = 9   this is the radius

9 * 9 * 3.14

254.34


500

A dog is leashed to a point in the center of a large yard, so the area the dog is able to explore is circular. The leash is 20 feet long. What is the area of the region the dog can explore?

1256

r = 20 

20 * 20 * 3.14

500

What is the radius of a circle with a circumference of 368.636

58.7


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