Radius/Diameter
Circumference
Arcs and Sectors
Circles in the real world
Concepts
100
Find the radius
9 inches
100
What is the circumference?
15.7 cm
100
A circle has an area of 12 ft². It is cut into 4 equal pieces. What is the area of each sector?
3 ft²
100
A bicycle wheel has a radius of 1 foot. If the bicycle wheel rotates one time, what distance is travelled?
6.28 feet
100
What is radius?
The radius is the distance between any point of the border (circumference) and the middle point.
200
Find the diameter
20 m
200
What is the circumference?
21.98 cm
200
A circle has a circumference of 22 feet. It is cut into 10 equal pieces. What is the length of each of the ten arcs?
2.2 ft
200
A large Jeep has a tire with a radius of 18 inches. Find the circumference of the wheel.
36π
200
What is diameter?
The diameter is the greatest distance between two points in the circumference. It can be represented by a straight line crossing the center of the circle. It is the radius time two.
300
Find the radius
18 ft
300
What is the circumference of a circle with radius 17 cm?
106.76 cm
300
A pizza is 16 inches long (the diameter). The pizza is cut into 8 pieces. What is the length of crust (circumference) on each piece? You can put the answer in terms of π
2π
300
Matt is learning to drive a car. The steering wheel in his car has a radius of 9 inches. His instructor says "Place your hands at 10 and 2." (1/3 of the circle) What is the area of the sector formed in terms of π?
27π in²
300
What is circumference?
The border of the circle. The outline of the circle. It is similar to the perimeter in polygons. C = πd = 2πr
400
If a circle has a circumference of 18.84 feet, what is the diameter?
6 feet
400
What is the circumference of a circle with a radius of 11.99 mm? (round to the nearest tenth)
75.3 mm
400
A pizza is 16 inches long (diameter). It is cut into 4 pieces. Jane eats 3 of the pieces. What is the area of pizza she is eating?
48π in²
400
John owns a circular pool in his back yard. If he swims around the pool, he swims 30π meters. What is the radius of this circle?
15 meters
400
What is π?
Pi is the ratio between the circumference and the diameter of a circle.
C= 2πr
500
If a circle has a circumference of 43.96 mm, what is the radius?
7 mm
500
A circle has a diameter of 12.5 inches. What is the circumference in terms of π?
12.5π inches
500
What is the area of the shaded region in terms of pi?
12π
500
A circle has a diameter of 28 inches. What is the area of a quarter of the circle? Give the approximate answer.
153.94 in²
500
What is radii?
Radii is the plural of radius.