Question

find CDE, if BAC=50 and BCA Is a right angle.
a) 40
b) 50
c) 90
d) 180

Answer 1

Because of the two sets of parallel lines, two pairs of corresponding angles are congruent, and the triangles are similar.

Since m<BAC = 50, then m<DCE = 50.

mBCA = 90, and m<DEC = 90

m<DCE + m<DEC + m<CDE = 180

50 + 90 + m<CDE = 180

m<CDE = 40