Page 206 - New Medley 4 Semester 1

We can represent an angle through a point and two rays.
Ray 1
Rays 1 and 2 are the two arms and the point where these

arms meet is the vertex of the angle.
Point
Mental Test Ray 2

Think of any two situations from your surroundings where you can observe

angles.

Naming an Angle

An angle has one vertex and two arms. Let us know how to name an angle.

The angle shown in the figure is called angle QPR or R
angle RPQ. Symbolically, it can be written as ∠QPR or

∠RPQ. We write vertex in the middle and the two points
of the arms on either side of the vertex. ∠ is the symbol

of the angle. P Q

We can also name an angle using numbers or small letters
of the English alphabet. For example,

x
1

∠1 ∠x

Regions of an Angle

The shaded portion in the figure is called the interior of ∠ABC.

Points L and M lie in its interior region.
A
The outside region of ∠ABC is called its exterior region. N
S
Points Q, R and S lie in its exterior region. M
R B
L
Points P and N lie on the angle because they are on Q
P
its arms. C

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