Question

calculator the value of a from the following figures

Answer 1

2nd 3a+15+2a-10=180(linear pair)                                                                                                        

5a+5=180

5(a+1)=180

a+1=180/5

a+1=36

a=35

3a+15=3*35+15=120

2a-10=2*35-10=60

for verification

120+60=180

180=180

3rd 3y+4y+5y=180(all angles on straight line)

12y=180

y=15

3y=3*15=45

4y=4*15=60

5y=5*15=75

for verification

45+60+75=180

180=180

Answer 2

I. 3a-15°=105° (V.O.A.)
3a=105°+15°
3a=120°
a=120°/3
a=40°
2.3a+15°+2a-10°=180°(L.P.)
5a+5°=180°
5a=180°-5°
5a=175°
a=175°/5
a=35°