tolng dijawab yg bener yh makasih # poin nya banyak loh

a. Sdt C yg bkn 3 & 4 = 180-70-60 = 50° Jd, karena C berpelurus dgn C 3&4, maka jml 180°. Dan C3+C4 = 180-50 = 130°
b. Besar B = 60° & B1 = B2. Maka B2 = 60/2 = 30°
c. D = 180-B2- (C yg tdk berno+C3)
= 180-B2- (50+ 130/2)
= 180-30- (50+65)
= 180-30-115
= 35°