Radius or Diameter?
A line that goes from the center of the circle to any point on the edge.
What is Radius
You are told the radius is 4 cm. Which formula would you use
What is C = 2πr
A circle has a radius of 4 cm.
What is the area of the circle?
Use 3.14 for pi
50.24cm2
The diameter is always smaller than the radius
False
A circle has a radius of 5 cm.
What is the circumference?
31.4cm
A line that passes all the way through the circle and through its center.
What is Diameter
The diameter of a circle is 10 cm. Which formula would you use?
What is C = πd?
A circle has a diameter of 10 inches.
What is the area?
78.5in2
You can find circumference if you only know the radius.
True
A circle has a diameter of 12 inches.
Find the circumference.
37.68in
This line is half as long as the diameter.
What is radius
You are told the distance across the circle is 8 cm. Which formula would you use?
What is C = πd?
A circular garden has a radius of 7 ft.
Find the area of the garden.
Use π ≈ 3.14.
153.86 ft2
The formula C = πd is the same as C = 2πr.
True
A circular track has a radius of 9 meters.
Find the circumference.
Use π ≈ 3.14.
56.52m
This line is twice as long as the radius
What is diameter
You only know the distance from the center to the edge is 6 cm. Which formula would you use?
what is C = 2πr?
A pizza has a diameter of 16 inches.
What is the area of the pizza?
(Leave answer in terms of π.)
64π in2
The radius goes across the entire circle.
False
A circle has a circumference of 62.8
What is the radius?
10
The circle’s measurement that helps find the circumference using the formula C = 2πr.
What is radius
You are given the diameter but accidentally use the radius formula. What must you do first?
what is Divide the diameter by 2 to get the radius?
A circular swimming pool has an area of 254.34ft2.
What is the radius of the pool?
9ft
If you double the radius, you get the diameter.
True
A circle has a circumference of 44 units.
Using π ≈ 3.14, what is the radius?round to the nearest whole number
7