Page 45 - Ganit Kaushal

Ex 5. Draw rough diagrams of two angles such that they have

(a) one point in common. (b) two points in common.
(c) one ray in common.
Sol. (a) ∠AOB and ∠COD, (b) ∠ABC and ∠DEF, G and H are two common
O is the only common point. points.
A
A E
B
O B G H
C C
D F
D
(c) ∠BOA and ∠AOC, B

OA is the common ray.
A

O
C
Ex 6. In each of the following figures, write the number of common points in the two angles marked by
small curves.
C D
(a) D (b)
F
E E
B C
A A B

Sol. (a) 3; B, E and C. (b) 4; B, C, E and F.

Exercise 2.2

1. In the adjoining figure, AB is a line. Are OA, OB and OC rays? There are three C
angles in the figure, one of which is ∠AOB. What are the other two?

A O B
2. How many angles are there in the adjoining figure? Name them. D C

A B
3. In the adjoining figure, name the six angles that have O as the vertex.

D
C
O
B
A

Lines and Angles 43