Download Geometry Name: Guided Notes Central Angles and Arcs Date

Geometry
Guided Notes
Central Angles and Arcs
Name: _____________________________
Date: _________________ Period: _____
Central Angle - an angle with its vertex at the center of the circle
Classification of Arcs:
Minor Arc is: less than 180° and is named using ______ letters
SemiCircle is: equal to 180° and is named using ______ letters
Major Circle is: greater than 180° but less than 360° and is named using _____ letters
Example #1:
∡AOB is the _____________ angle
_______ is a minor arc
_______ is a major arc
IMPORTANT:
The measure of a minor arc is equal to the measure of its central angle.
The measure of a major arc is 360° minus the measure of its associated minor arc.
Example #2:
̂
Find
̂
Find
Find
̂
Find m∡AOB
Geometry
Guided Notes
Central Angles and Arcs
Name: _____________________________
Date: _________________ Period: _____
Arc Addition Postulate -The measure of an arc formed by two adjacent arcs is the sum of the measures of the
two arcs.
Example #3: Find the measure of each arc.
NOTE: In the same circle, or in congruent (≅) circles, two arcs are ≅ iff their central angles are≅.
Example #4: Find the measure of ̂ and ̂ . Are the arcs congruent?
Geometry
Name: _____________________________
Guided Notes
Central Angles and Arcs
Date: _________________ Period: _____
Example #5: Use the graph to determine the measure of each arc.
Example #6:
Example #7:
Example #8:
Example #9:
m∡AOD