Circles

Central angle: angle=arc

Central angles have a vertex at the center of the circle. The arc created by the two radii is equal to the angle.

Inscribed Angle: angle=1/2*arc or arc=2*angle

Inscribed angles must have a vertex touching the circle. The angle is half of the outside arc or the arc is twice the angle inside.

Multiple Choice

Which of the following represents a central angle?

Multiple Choice

Which of the following represents a inscribed angle?

Multiple Choice

What is does x equal?

• $$160\degree$$

• $$80\degree$$
  

• $$40\degree$$
  

• $$360\degree$$
  

Math Response

What is the measure of the missing angle in degrees?

Type answer here

Correct Answer: 51

Deg^°

Rad

Multiple Choice

What is the formula for circumference of a circle given the diameter?

• C = π r
• C = 2 π r
• C = π d
• C = 2 π d

Multiple Choice

If the circumference of a circle is 22π , what is the diameter?

• 22 ft
• 11 ft
• π ft
• 0 ft

Multiple Choice

If the circumference of a circle is 22 π ft, what is the radius?

• 22 ft
• 11ft
• π ft
• no ft

Multiple Choice

A _____ is half of a circle.

• circumference
• pi
• semicircle
•  composite figure

Multiple Choice

what is the formula for finding area of a circle

• C = π r²

• A = π r²

• A = π r² / 2

• C = 2 π r

Multiple Choice

If the area of circle is 100 π , find the radius of the circle.

• 10 π
• 10
• 50
• 50 π

Multiple Choice

FIND THE ARC LENGTH OF THE BOLDED ARC

• A
• B
• C
• D

Multiple Select

Which of the following formulas calculates the arc length of a circle? (Select ALL that apply.)

• $$\frac{\theta}{180}\times2\pi r$$

• $$\frac{\theta}{360}\times2\pi r$$

• $$\frac{\theta}{360}\times\pi d$$

• $$\frac{\theta}{360}\times\pi r^2$$

Multiple Choice

Calculate the area of the sector.

• 4248 m²

• 7.9 m²

• 2827.4 m²

• 11.8 m²