Parts of a Circle

Review Circles and PI

Some text here about the topic of discussion

​Parts of a Circle

Multiple Choice

The _______ is the line segment of a circle that goes from the center to the outside edge.

• diameter

• center

• circumference

• radius

Multiple Choice

A _________ of a circle is a line segment that passes

through the center of the circle and whose endpoints lie on the

circle.

• radius

• diameter

• center

• circumference

Multiple Choice

The _____________ of a circle is the distance around the circle.

• diameter

• radius

• center

• circumference

​The radius is always half the length of the diamter.

If the diamter is 10 then the radius is 5.

If the radius is 7 then the diameter is 14.

An equation that represents this is d = 2r.

Multiple Choice

If the diameter of a circle is 20 meters what is its radius?

• 15 meters

• 12 meters

• 10 meters

• 5 meters

Multiple Choice

If the radius of a circle is 6 inches then what is the diameter?

• 12 inches

• 18 inches

• 24 inches

• 36 inches

Multiple Choice

What would be the diameter of this circle?

• 5 cm

• 7.5 cm

• 10 cm

• 15 cm

Multiple Choice

The diameter of the circle is shown, what is the radius?

• 4 ft

• 8 ft

• 12.8 ft

• 2 ft

Multiple Choice

What is the diameter of this circle? The radius is shown.

• 8 yd

• 16 yd

• 160 yd

• 12 yd

Multiple Choice

What is the diameter of the circle?

• 1.6 in

• 3.2 in

• 6.4 in

• about 9 in

Multiple Choice

What is the radius of this circle? The Diameter is shown.

• 7 m

• 14 m

• 12 m

• 56 m

​The ratio fo any circumference to diameter is always equal to Pi. Pi is approximaltey 3.14.

​This is where the equation C = 3.14 d comes from.

We will use this in the next few questions to find circumference.

Multiple Choice

If I know the diameter of a circle I can find its circumference by multiplying by what number?

• 2

• 3

• 3.14

• 6.28

Multiple Choice

If a circle has a diameter of 10 what would be the circumference?

• 3.14

• 31.4

• 314

• 3114

Multiple Choice

If a circle has a diameter of 5 then the circumference would be?

• 5 x 3.14

• 5 x 6.28

• 5 x 2

• 5 x 3

Multiple Choice

How could I calculate the circumference of the circle shown?

• 24 x 2

• $$24\div2$$  

• 24 x 6

• 24 x 3.14

Multiple Choice

How could you calculate the circumference of the circle shown?

• $$8\times3.14$$  

• $$4\times3.14$$  

• $$16\times3.14$$  

• $$24\times3.14$$  

Multiple Choice

If you knew the circumference of a circle and wanted to find the diameter then what would you need to do?

• multiply by pi

• divide by pi

• divide by 2

• multiply by 2