Vocabulary
Radius from Diameter
Diameter from Radius
Circumference
Area of a Circle

100

A round plane figure whose boundary (the circumference) consists of points equidistant from a fixed point (the center)

A circle 

100

How do you find the radius of a circle when given the diameter? 

divide the diameter by 2 

100

How do you find the diameter of a circle when given the radius? 

multiply the radius times 2

100

What is the formula for finding the circumference of a circle? 


100

What is the formula for finding area of a circle? 


200

A straight line from the center to the circumference of a circle

Radius 

200

What is the radius of a circle that has an 8-foot diameter? 

4 ft. 

200

What is the diameter of a circle with a radius of 5 inches? 

10 inches

200

Find the circumference of this circle when pi=3

84 m. 

200

Find the area of this circle when pi = 3 

588 m. 

300

A straight line passing from side to side through the center of  a circle

Diameter 

300

What is the radius of this circle? 

6 cm. 

300

What is the diameter of a circle with a radius of 100 feet? 

200 ft. 

300

What is the circumference of a circle with a radius of 6 inches when pi = 3.14?

37.68 inches 

300

What is the area of a circle with a radius of 5.5 inches when pi = 3.14? 

94.985 inches 

400

the distance around the circle. It is the circle's perimeter

circumference 

400

What is the radius of this circle? 

3.1 mm 

400

What is the diameter of this circle? 

28 m

400

What is the circumference of this circle when pi = 3.14? 

28.26 in. 

400

What is the area of this circle when pi = 3.14? 

28.26 in. 

500

The amount of space inside the boundary of a flat (2-dimensional) object such as a triangle or circle

Area 

500

What is the radius of a circle that has a 325-foot diameter? 

162.5 ft. 

500

What is the diameter of a circle with a radius of 215 inches? 

430 in. 

500

What is the circumference of this circle when pi = 3.14? 

19.468 mm 

500

What is the area of this circle when pi = 3.14? 

30.1754 mm