Jawabanmu

2014-06-10T21:55:46+07:00
L = 1/2 x jumlah sisi sejajar x t
49 = 1/2 x (8 + x) x 7
49 : 1/2 = (8 + x) x 7
49 x  2  = (8 + x) x 7
   98      = (8 + x) x 7
98 : 7    = 8 + x
   14      = 8 + x
14 - 8    = x
6 cm     = x

DC = 6 cm
1 5 1