Bunuel
If AC = BC and CD = DE then, in terms of x, the value of y is

Note: Figure not drawn to scale
A. x
B. 180 - 2x
C. 90 - 2x
D. 4x - 180
E. 45 + x/4
When we add the given information to the diagram we get:

In an isosceles triangle, the angles opposite the equal sides are always equal.
This means ∠A =
x° Also, since the angles in a triangle must add to 180°, we know that ∠ACB =
180 - 2x The angles in the other triangle are a little trickier, so, let's label them
k to get the following diagram:

Since the angles in a triangle must add to 180°, we can write:
k + k + y = 180Simplify:
2k + y = 180Subtract y from both sides:
2k = 180 - yDivide both sides by 2 to get: :
k = (180 - y)/2So, we can add this information to our diagram:

Finally, since opposite angles are equal, we can write the following equation:
180 - 2x =
k = (180 - y)/2 [we need to solve this equation for y]Multiply both sides of the equation by 2 to get:
360 - 4x = 180 - ySubtract 180 from both sides of the equation to get:
180 - 4x = -yMultiply both sides of the equation by -1 to get:
-180 + 4x = y, which can be rearranged as follows:
y = 4x - 180Answer: D
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