Finding Circumference
Circles
More Circles
Area
Circumference & Area
Vocabulary
100
What does circumference mean?
Circumference is the distance around the outside of a circle.
100
What is the radius of a circle with a diameter of 22 cm?
r = radius
d = diameter
r = d/2
r = 22/2
r = 11 cm
100
What is the radius of a circle with a diameter of 12 cm?
6 cm
100
What does area mean?
Amount of space that a shape (circle) is taking up.
100
What is the area of a circle with radius 10m?
314 m2
100
The distance around the outside of a circle.
Circumference
200
What is the circumference of a circle with a diameter of 2cm?
C = circumference
d = diameter
C = Pi x d
C = Pi x 2
C = 6.28 cm
200
What is the radius of a circle with the diameter of 126 cm?
r = radius
d = diameter
r = d/2
r = 126/2
r = 63 cm
200
Which is longer the radius or diameter?
Diameter
200
What is the area of a circle with a radius of 35cm?
3846.5 cm2
200
What is the circumference of a circle with radius 15 cm?
94.2 cm
200
Any line segment from the center of a circle to a point on the circle.
Radius
300
What is the circumference of a circle with a diameter of 6 cm?
C = circumference
d = diameter
C = Pi x d
C = Pi x 6
C = 18.84 cm
300
What is the diameter of a circle with the radius of 14 cm?
r = radius
d = diameter
d = r x 2
d = 14 x 2
d = 28 cm
300
The diameter of a circle is 46 cm what is the radius of that circle?
23 cm
300
What is the equation for area of a circle?
Area= 3.14 x r2
300
What is area of a circle with diameter of 20 ft? 
314 ft2
300
THe measure of the amount of unit squares it takes to cover a figure.
What is area?
400
What is the circumference of a circle with the radius of 4cm?
C = circumference
r = radius
C = Pi x 2 x r
C = Pi x 2 x 4
C = 25.12 cm
400
What is the diameter of a circle with a radius of 100 cm?
r = radius
d = diameter
d = r x 2
d = 100 x 2
r = 200 cm
400
What does pi equal?
3.14
400
What is the area of a circle that has a diameter of 22ft?
?
379.94 ft2
400
*** DOUBLE JEOPARDY ***
Circumference of a circle is 18 cm. What is the radius? (write your answer with 2 digits behind decimal--no rounding)
2.86 cm
400
The mathematical name for the ratio of a circle's circumference to its diameter. It's value is about 3.14
Pi
500
What is the circumference of a cirlce with a radius of 6 cm?
C = circumference
r = radius
C = Pi x 2 x r
C = Pi x 2 x 6
C = 37.68 cm
500
The distance from the tip of a slice of pizza to the crust on the outside is 6 in. What is the diameter of the pizza.
r = radius
d = diameter
d = r x 2
d = 6 x 2
r = 12 inches
500
How do you find the circumference of a circle?
Multiply 3.14 x the Diameter
3.14 x D
500
What is the area of a circle with a diameter of 5 cm?
19.625 cm2
500
Circumference of a circle is 21.98. What is the radius?
3.5 cm
500
Any line segment from a point on a circle through the center point to another point on the circle.
What is Diameter?