Circle information
Circumference
Area
Others
Extra
100

What would you use from your protractor kit to make a circle?

Compass

100

What does circumference mean?

the distance around a circle (like perimeter of square)

100

What is the equation for the area of a circle?

A = pi x r x r

100

what is the area of a circle with a 2.4 cm radius? (to the nearest tenth)

A=3.14x 2.4 x2.4 A=18.1cm^2

100

If the radius is 10 inches what is the diameter

20 inches

200

What is (distance around) divided by (diameter)? 

Pi

200

What is the equation for circumference? (both equations)

c=pi x d or c= pi x 2 x r

200

If you have a circular mirror with a radius of 20cm, what is its area?

A= π x 20x 20cm A = 400π cm2

200

true or false: If the radius of a circle is doubled, then the circumference is also doubled?

Always true

200

If the circumference is 220 ft what is the radius? (rounded to the nearest hundredth)

35.03 ft

300

What is (distance around) divided by (radius)? 

2pi

300
What is the circumference of a circle if it has a diameter of 5.2 m?
answer: 16.33 m c=3.14 x 5.2 c= 16.33 m
300

A circle has a diameter of 25cm. What is it's area?(2 decimal places)

r=12.5cm 

A=π x 12.5 x 12.5 

= 490.63cm2

300
When drawing a circle graph, what tools should you use: 1) to measure each section? 2) to draw the circle? 3) to find the radius or diameter?
1) to measure the sections you use a protractor 2) to draw the circle you need a compass 3) to find the radius or diameter you need a ruler
300

The circumference of a circle is 78.5 inches what is the area of the circle 

radius 12.5 

area = 12.5*12.5* 3.14

490.625 inches squared

400

What are the equations for finding the radius and diameter?

radius= d ÷ 2 diameter =r x 2

400

If you are given a radius of 6cm, what is the circumference?

12π cm

400

The area of a circle is about how many times the square of its radius? a.1 b.2 c.3 d.4

answer: 3

400
The measure of space covered by a 2-D shape is the definition for what? And Find this if you have a radius of 5cm.
area =78.5 cm^2
400

What is the area of a quarter circle with a radius of 10ft ?

78.5 ft squared

500

What is the radius of a circle with a diameter of 95m? (leave your answer in cm)

4750 cm

500

What is the diameter of a circle that has a circumference of 221mm? (round to nearest hundredth)

c= π x d 221mm = 3.14 x d 221/3.14 =d d=70.38mm

500

Fourty-four metres of fencing is used to make a circular enclosure. What is the area of the circle? (to the nearest square metre)

44 is the circumference 

44=3.14 x d 14.01= d r=7.01 A= π x r x r A= 3.14 x 7.01 x 7.01 A=154 m2

500

The outer fence  has an outside diameter of 28mm and the iniside fence has a diameter of 8mm. What is the area of the outer ring to the nearest hundredth of a square millimeter?

414.48mm^2

500

What is the area of a semi circle with a diameter of 18 cm

254.34 cm^2

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