Lesson 3: The Circle

A full reel of cable has a diameter of 60 inches. A job requires 314 feet of cable. How many turns of cable should be taken off the reel? a. 10 turns b. 15.7 turns c. 16.7 turns d. 20 turns

d. 20 turns

The diameter of a circle is always 3.14 times its circumference.

False

The radius of a circle is equal to twice its diameter.

False

The distance around a circle is called the ? . a. circumference b. girth c. perimeter d. span

a. circumference

A circle has a diameter of 18 centimeters. What is the area of the circle? a. 25.8 cm^2 b. 88.7 cm^2 c. 177.5 cm^2 d. 254.3 cm^2

d. 254.3cm^2

The butt of a pole has a diameter of 50 inches. What is its circumference? a. 15.70" b. 15.92" c. 78.5" d. 157.0"

157.0"

If the diameter of a circle is 32 inches, what is the radius? a. 16" b. 18" c. 23" d. 64"

a. 16"

If the radius of a circle is 2.5 meters, what is the circumference? a. 7.85 m b. 15.7 m c. 19.63 m d. 31.4 m

b. 15.7m

A 40-foot, class 2 pole has a minimum top circumference of 50 inches. What is its minimum diameter? a. 7.96" b. 15.92" c. 62.8" d. 157.0"

b. 15.92"

The length of any line segment that connects two points on the circle and passes through the center is called the ? . a. cord b. diameter c. radius d. sector

b. diameter

The distance from the center of the circle to any point on the circle is called the ? . a. arc b. cord c. diameter d. radius

d. radius

If the circumference of a circle is 85 millimeters, what is the diameter? a. 13.6 mm b. 27.1 mm c. 54.2 mm d. 267 mm

27.1 mm

In many calculations, 3.14 or 3 1/7 are typically used to approximate π.

True

The diameter of a circle is equal to twice its radius.

True

A circle is a set of all points in a plane that are all the same distance from a common point called the ? . a. center b. middle c. tangent d. vertex

a. center

Which equation shows the correct relationship between the radius and the area of a circle? a. A = πr^2 b. A = r^2π c. r = A^2π d. r = square root of πA

a. πr^2

What radius, in millimeters, is needed on a trundle wheel so that one rotation will measure a distance of one meter? a. 157.0 mm b. 159.2 mm c. 636.9 mm d. 1,570.0 mm

b. 159.2mm

If the radius of a circle is nine centimeters, what is the diameter? a. 4.5 cm b. 18.0 cm c. 30.6 cm d. 81.0 cm

b. 18.0cm

The ratio of the circumference of a circle to the ? is represented by the Greek letter π. a. area b. diameter c. radius d. width

b. diameter

A trundle wheel, used to measure distances, has a radius of eight inches. How many feet has it traveled on the ground when it has made 300 revolutions? a. 125.6' b. 628' c. 1,256' d. 2,512'

c. 1,256'

A circle has a diameter of five inches and a circumference of 15.71 inches. What is the ratio of the circumference to the diameter? a. 0.318 b. 0.318" c. 3.142 d. 3.142"

c. 3.142

Which equation shows the correct relationship between the radius and the diameter of a circle? a. r = 2d b. d = 1/2r c. d = 2r d. r = 2/d

c. d = 2r

Find the area of a circle that has a radius of seven inches. a. 21.98 in^2 b. 43.96 in^2 c. 69.0 in^2 d. 153.86 in^2

d. 153.86 in^2

Which equation shows the correct relationship between the diameter and the circumference of a circle? a. d = π/C b. C = π/d c. C = d/π d. d = C/π

d. d= C/π