Circles and Arcs

Circles and Arcs

By Deb Scott

​Objective: Find measures of central angles, arcs, circumference, and arc lengths

Open Ended

Name two major arcs.

Open Ended

Name two minor arcs.

Multiple Choice

Which of the following is a semicircle?

• arc MHT

• arc MTH

• arc HT

Multiple Choice

Find the circumference of the circle

• 50.24 yd

• 25.12 yd

• 11.14 yd

Multiple Choice

Find the circumference of the circle

• 18.84 cm

• 75.36 cm

• 37.68 cm

Arc Length

Arc Length is the length of a portion of the circumference.

To find this we multiply the circumference by the fraction of the circle the arc subtends.

The fraction of the circle is determined by dividing the central angle by 360.

Example 1: Find length of minor arc AB.

Multiple Choice

A central angle of a circle measures  $$230\degree$$  and its radius is 6 cm. What is the length of the arc intercepted by the angle?

• 12.04 cm

• 24.08 cm

• 144.51 cm

• 72.26 cm

Multiple Choice

What is the length of the blue arc?

• 45⁰
• 3.9 mi
• 5.9 mi
• 7.9 mi

Multiple Choice

Name the circle

• Circle A
• Circle B
• Circle C
• Circle D

Multiple Choice

• A
• B
• C
• D

Multiple Choice

• A
• B
• C
• D

Multiple Choice

Which is true of a minor arc?

• It forms half a circle.
• It forms a whole circle.
• It measures greater than 180 degrees. 
• It measures less than 180 degrees.

Multiple Choice

Which words describe two circles with the same radius?

• Similar Circles
• Concentric Circles
• Congruent Circles
• Semicircle

Multiple Choice

A ____ angle is an angle whose vertex is a the center of a circle.

• supplementary
• complimentary
• central
• obtuse

Multiple Choice

If the endpoints of an arc lie on a diameter, the arc is a ....

• major
• minor
• semicircle
• sector

Multiple Choice

Which is true of a major arc?

• Forms half a circle.
• Forms a whole circle.
• Measures greater than 180 degrees.
• Measures less than 180 degrees.

Multiple Choice

Which of the following would be a major arc in the diagram?

• BC
• BCD
• CD
• AB

Multiple Choice

What is the measure of arc PQ?

• 47
• 57
• 67
• 77