tolong ya kak dengan caranya

Sisi sisi alas = 12,15,6,7,x
x = triple 6,8,(10)

Keliling Alas = 12+15+6+7+10 = 50cm
L selimut = 50×18 = 900cm²
L 2Alas = (15×6)+[(15+7)×6÷2]
L 2Alas = 90+66 = 156cm²×2=312

L Seluruh = 900+312=1212cm²