10-6 Circles and Arcs. Learning Goals 1. To find the measures of central angles and arcs. 2. To calculate the circumference and arc length. What is the measure of the angle all the way around B?. B. C. What is the measure of the angle all the way around B? 360˚. B. C. - PowerPoint PPT Presentation
Transcript of 10-6 Circles and Arcs
10-6
Circles and Arcs
Learning Goals
1. To find the measures of central angles and arcs.
2. To calculate the circumference and arc length.
What is the measure of the angle all the way around B?
B C
What is the measure of the angle all the way around B?
360˚
B C
If m ABC = 60°,
B C
A
If m ABC = 60°,
then the m ABC = ?
B C
A
If m ABC = 60°,
then the m ABC = 300°.
B C
A
Central Angle
An angle whose vertex is at the center of a circle.
CentralAngle
Arcs
The sections of the circle separated by the central angles.
arcs
Arcs are measured by their corresponding central angle.
m ABC = 80
m AC = ?
A
B
CD
80°
Arcs are measured by their corresponding central angle.
m ABC = 80
m AC = 80
A
B
CD
80°
Arcs are measured by their corresponding central angle.
m ABC = 80
m AC = 80
m ADC = ?
A
B
CD
80°
Arcs are measured by their corresponding central angle.
m ABC = 80
m AC = 80
m ADC = 280
A
B
CD
80°
Minor arc: less than 180° and 2 letters are used for the name.
Major arc: greater than 180° and 3 letters are used for the name.