Jawabanmu

2014-06-04T13:00:28+07:00
AD² = 20² - 15² = 400 - 225 = 175
AD = 5√7
BC = 5√7 + 20
Luas ABCD = 1/2 . ( 5√7 + 5√7 + 20) . 15 = (5√7 + 10) . 15 = 150 + 75√7