Luas permukaan bangun diatas adalah...

dik :
L1 = 15 cm
L2 = 20 cm
t = 30 cm

dit : Lp

Jawab :
Lp = 2. (1/2) . L2 . L1+ 2. L1. t + L2 . t
Lp = L2 . L1 + 2 . L1 . t + L2 . t
Lp = 20 . 15 + 2 . 15 . 30 + 20. 30
Lp = 300 + 900 + 600
Lp = 1800 cm²