Answer:
135°
Explanation:
we are given that the bottom leftmost angle is 50, so its opposite angle is 50 since opposite angles are always congruent.
the angle opposite 100 degrees is 100, the last angle in the left triangle is 30 since 180 - 100 - 50 = 30. (all angles in a triangle equal 180)
the angle to the right of the 70 is 80, since a line is a flat angle = 180 and
180-30-70 = 80
the angle opposite 55 is 55
the question mark would be 55+80=135, since the outside angle of a triangle is equivalent to the sum of the farthest 2 inside angles.