Page 86 - Math Course 1 (Book 2)

Geometry: Angles

Mo. 9

Lesson 4 sides

The rays are called sides of the angle.
→
side AB
KEY CONCEPTS: B
1. Identify and name the parts of an angle. A 4
2. Measure and classify angles.
→
3. Identify and use congruent angles and the side AC
bisector of an angle. C
vertex
The common endpoint is the vertex.
MO. 9 - L4a

Parts of an Angle B
Vertex A A 4

Vocabulary A-Z C

Let us learn some vocabulary interior
An angle divides a plane into three distinct parts.
Points C and B lie in the interior of the angle.

ray
rd
A ray is part of a line. It has one endpoint and The 3 part is points
extends indef nitely in one direction. A, D and E which lie on
the angle.
E

F The f gure
G shows ray EF exterior

An angle divides a plane into three distinct parts.
Points F and G lie in the exterior of the angle.

opposite rays
If you choose a point on a line, that point
determines exactly two rays called opposite rays. Let’s Begin

Q P R
m
Angles and Their Parts
line m, is separated into two opposite rays from point
→ → Examples
P as PQ and PR

angle A. Name all angles that
An angle is formed by two non collinear rays that have B as a vertex.
have a common endpoint.

common Answer
endpoint ∠5, ∠6, ∠7 and∠ABG

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