Please solve for x
thank you ♡

The given two angles are called vertically opposite angles which are generally equal.

(Vertically opposite angles are those angles which are opposite to each other when two lines cross)

So,

Now, for verification,

3x+178° = 3(-20) +178° = 118°

6x+238= 6(-20)+238° =118°

according to the triangle sum theorem, all the angles in a triangle must add up to 180 degrees. if we know one angle is already 90, we do 180-90=90. the other 2 angles must add up to 90, exactly.

step-by-step explanation: