Page 143 - New Medley 5 Semester 2

C. Name the vertices, arms and angles in each of the following.
1. R 2. C 3. O Q

A
E
B
P
T
S
D
D. How many angles do you observe in the following figures? Write them.

1. R 2. I J 3. Q
S K P R

Q
P
L S
O
X
E. Fill in the blanks:
1. If two lines have a common point, the lines are called .

2. A reflects an exact position in space.
3. The number of points which determine a plane is .

4. In a plane, the two non-intersecting lines are called .

5. Each angle has one and two .

Measure of an Angle

The spread between two arms of an angle is measured A
in ‘degrees’. A degree is a unit of measurement used

for measuring angle. The degree is represented by the
symbol (°). Suppose, the measure of ABC is 45 degrees.

Then, it is written as 45° in symbol. B C

Consider the measure of angles formed by a pair of pencils and matchsticks.

Can you say which pair forms greater angle?

Length of arms does not affect the measure of an

angle. Wider gap shows greater angle and narrow

gap shows smaller angle.

141