Jawabanmu

2014-05-27T11:26:14+07:00
L = 1/2 . D₁ . D₂\
81 =  1/2 . 18  . (2x+3)
9 = 2x + 3
6 = 2x
3 cm = x

b) panjang diagonal kedua
= 2x+3
= 2.3 + 3
=9 cm
1 1 1