exterior/interior angles

[late jackal]

How do you work this out ??

[desert storm]

C 180-106=74

D 180

Angle on a straight line adds up to 180°

B
180-98=82
180-71=109
This shape has 5 sides so the sum of angles in this shape is 540
So 540-82-109-135-90=124
So your b should be 180-124=56°

[twilit briar]

for B why cant you also do 180-135 and 180-90?

[late jackal]

Oh so why do u take away b separately

[desert storm]

I don't know