Radius
If the diameter of a circle is 10 units, then what is the length of the radius?
5 units
If the radius is 5 units, then what is the length of the diameter?
10 units
A circle has a diameter of 2 inches. What is the circumference?
6.28 inches
A circle has a radius of 5 feet. What is the area of this circle?
78.5 feet2
A line segment that goes from one end of the circle to the other through the center.
Diameter
If the diameter is 100 inches, then what is the length of the radius?
50 inches
If the radius is 20 yards, then what is the length of the diameter?
40 yards
A circle has a diameter of 4 inches. What is the circumference?
12.56 inches
A circle has a radius of 10 inches. What is the area?
314 inches2
A straight line from the center of the circle to any point on the circle.
Radius
If the diameter is 15 cm, then what is the length of the radius?
7.5 cm
If the radius is 4.5 feet, then what is the length of the diameter?
9 feet
A circle has a radius of 5 inches. What is the circumference?
31.4 inches
A circle has a radius of 9 meters. What is the area?
254.34 meters2
The distance around the outside of a circle.
Circumference
If the diameter is 25 feet, then what is the length of the radius?
12.5 feet
If the radius is 10.5 units, then what is the length of the diameter?
21 units
A circle has a radius of 4.5 inches. What is the circumference?
28.26 inches
A circle has a diameter of 10 inches. What is the area?
78.5 inches2
The amount of space inside a circle.
AREA
If the diameter is 0.5 inches, then what is the length of the radius?
0.25 inches
If the radius is 1.15 units, then what is the length of the diameter?
2.3 units
A circle has a diameter of 12.5 inches. What is the circumference?
39.25 inches
A circle has a diameter of 100 inches. What is the area?
7850 inches2
How are perimeter and circumference similar?
They both measure the distance around the outside of something.