Question

In the figure below, ABC is a right triangle. a+b= 150 degrees, and c+d= 35 degrees. Find x.

A. 150
B. 115
C. 85
D. 25

Answer 1

the answer is C. if you do some simple geometry you find that d is no more than 5 degrees, and it's just subtracting and adding from there

Answer 2

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

`(a+b) + 90 + (c+d) + x = 360`

`150 + 90 + 35 + x = 360`

`275 + x = 360`

Subtracting 275 from both sides

`275 + x - 275 = 360 - 275`

`x = 85`°

Hence the option is C. (85) : Answer

Hope it will help :)