Step-by-step explanation:
the sum of all internal angles of any quadrilateral has to be 360°.
like in rectangles (4×90 = 360).
in this trapezoid 2 of the rectangle angles are just a little bit distorted : one angle gets more, which it takes from the other. but together these 2 angles must be 180°, as the remaining 2 angles are "normal" rectangle angles of 90°.
therefore
180 = angle 3 + angle4 = 160 + angle4
angle4 = 180 - 160 = 20°
and therefore,
angle2 + angle4 = 90 + 20 = 110°
