Answer:
Step-by-step explanation:
y is the remote exterior angle. The remote exterior angle has the strange property that it is equal to the two remote interior angle. The two remote interior angles are the two, neither of which is the supplement of the exterior angle
So y = x/2 + x/2 which are marked as being opposite equal angles.
1/2 x + 1/2 x = x
y by substitution is = x /2 + x/2
y = x
