Problem Solving (PS) | Re: In the figure above, what is the value of x in terms of a, b and y?

We know that the sum of angles in a triangle is 180 degree.
In bigger triangle, y + 2a + 2b = 180

Similarly, x + a + b = 180 degree in the smaller triangle.
Multiplying by 2, we get 2x + 2a + 2b = 360
Therefore, 2x + 180 - y = 360 => 2x = 180 + y

But we know that x = 180 - (a+b)

So 2x = 180 + y => x + 180 - (a+b) = 180 + y
x = y + a + b(Option D)

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