Answer:
128 deg
Explanation:
The sum of the measures of the angles of a polygon of n sides is
(n - 2)180
A trapezium has 4 sides, so the sum of the measures of the angles is
(4 - 2)180 = 2(180) = 360
m<CBE + m<C + m<D + m<DEB = 360
Angles ABC and CBE are a linear pair so the sum of their measures is 180 deg.
m<ABC + m<CBE = 180
115 + m<CBE = 180
m<CBE = 65
m<C = x
m<D = 90
Angles DEB and DEF are a linear pair so the sum of their measures is 180 deg.
m<DEB + m<DEF = 180
m<DEB + m<103 = 180
m<DEB = 77
m<CBE + m<C + m<D + m<DEB = 360
65 + x + 90 + 77 = 360
x + 232 = 360
x = 128
Answer: 128 deg