Alright, lets get started.
These two triangles ABC and ACD are jointly forming a polygon having 4 sides ABCD.
The sum of all internal angles of a polygon having 4 sides = 360
∠A + ∠B + ∠C + ∠D = 360
Plugging the values of each angle
[tex] (a+b) + 90 + (c+d) + x = 360 [/tex]
[tex] 150 + 90 + 35 + x = 360 [/tex]
[tex] 275 + x = 360 [/tex]
Subtracting 275 from both sides
[tex] 275 + x - 275 = 360 - 275 [/tex]
[tex] x = 85 [/tex]°
Hence the option is C. (85) : Answer
Hope it will help :)
