Circle Terms
The distance from the center of a circle to the outside; also half of the diameter
Radius
The diameter of this circle is 5 yd, what is the radius?
2.5 yd
Mandie wants to put some lace trim around the edge of a round tablecloth. If the tablecloth has a diameter of 6 feet, will 18 feet of lace be enough trim? Why or why not?
No, because the circumference is 18.84 ft
The diameter for this circle is 10 m, find the circumference. Use pi = 3.14
What is 31.4 m
The radius of this circle is 2 in, find the area. Use pi = 3.14
12.56 square inches
The distance around a circle
Circumference
The radius of this circle is 15.6 m, find the diameter
31.2 m
Gotcha Covered, Inc. manufactures canvas covers for above-ground pools. If Mrs. Alonso wants to purchase a cover for her pool that has a radius of 8 ft, how many square feet of canvas is needed? Use pi = 3.14
200.96 square feet
The radius for this circle is 13 ft, find the circumference. Use pi = 3.14
81.64 ft
The diameter of a circle is 10 ft, find the area. Use pi = 3.14
78.5 square feet
This is the longest line that can be drawn through a circle. There are infinitely many, all with the same length.
Diameter
The radius of a circle is 5/14 cm, find the diameter
5/7 cm
A unicycle tire has a radius of about 13 inches. Estimate how far the unicycle would travel in 20 rotations.
520 inches
The diameter of this circle is 49 in, find the circumference. Use pi = 22/7
154 in
The radius of this circle is 7/2 cm. Find the area; use pi = 22/7
77/2 or 38.5 square centimeters
The inside of a circle, found by squaring the radius and multiplying it by pi
Area
Estimate the radius of a circle with a circumference of 96 in. (Use pi = 3)
16 in
Julian’s mechanical pencil uses 0.9 mm lead, which means the cylindrical piece of lead has a diameter of 0.9 mm. What is the circumference of his mechanical pencil lead?
2.826 mm
The radius for this circle is 2.25 cm, find the circumference.
14.13 cm
The radius of this circle is 1.5 m, find the area
7.065 square meters
The ratio of circumference to diameter
pi
If the circumference of a circle is 18.84 ft, what is the circle's diameter? Use pi = 3.14
6 ft
Hector wants to cover a quarter of his pizza with pepperoni. If the diameter of the pizza is 12 inches, how many square inches will be covered with pepperoni?
28.26 square inches
The radius of a circle is 0.8 yd. Find the circumference. Use pi = 3.14
5.024 yd
The diameter of a semicircle is 6 in. Find the area using pi = 3.14
14.13 in