Find the measure of the third angle of a triangle given the measure of two angles are 86º and xº.

a) (86-x)
b) (90-x)
c) (94-x)
d) (180-x)

The total degrees in a triangle is 180. if you add the angles up, it should equal. if we say that the angle of the third angle is y, our equation looks like this
y+x+86=180
if we solve for y, we get
y=180-86-x, which you can solve for for your answer

The correct answer would be A, 86-x

the sum of a triangle will always be 180 the grease.