Question

find the size of unknown angle.​

Answer 1

Answer:

7a + 2a = 180 (Linear pair )

or 9a = 180

or a = 20

So, 7a = 140

2a = 40

Therefore, x = 7a = 140 (vertically opposite angles)

y = 2a = 40

Answer 2

Step-by-step explanation:

2a=y                              (vertically opposite angles)

7a=x                               (vertically opposite angles)

=>7a+2a=180                (linear pair)  

= 9a=180

= a=180/9

=a=20

=>2a=2*20=40

=>7a=7*20=140

=>x=140

and,

y=40