Week 1
Warm Up
03.21.12
Section
10.2 Day 1
Central
Angle
I will identify properties of arcs.
An angle whose vertex is the center of a circle.
Minor Arc
A central angle less than 180⁰
Major Arc
A central angle more than 180⁰
Simicircle
A central angle equal 180⁰
Rule 1
Arcs are named by their endpoints.
Minor
Arcs
Two endpoints. AB
Major
Arcs
Endpoints and point on the arc.
ACB
Rule 2
Minor
Arcs
Major
Arcs
Arc measures are defined by their central angle.
Ex 1
a.
b.
c.
P 26
Arc Addition Postulate
The measure of an arc formed by two adjacent arcs
is the sum of the measures of the two arcs.
Ex 2
a.
b.
= 230°
Do 1:
Assignment:
Textbook Page 607, 1 – 8 and 12 – 38 all