Jawabanmu

2014-05-06T11:47:51+07:00
< B = < D = 105'
<(A + B + C + D) = 360'
< C = 360' - (< A + < B + <D)
       = 360' - (80'+ 105' + 105')
       = 360' - 290'
       = 70'
Jadi < C = 70' dan < D = 108'