no.28 ya...plis....dgn cara

Kelas 8 Matematika
Bab Bangun Ruang

s = 1/2 . keliling
s = 1/2 . (8 + 14 + 18)
s = 1/2 . 40
s = 20 cm

L = √(s . (s - a) . (s - b). (s - c))
L = √(20 . (20 - 8) . (20 - 14) . (20 - 18))
L = √(20 . 12 . 6 . 2)
L = √(4 . 5 . 144)
L = 24 √5 cm²

Volume = luas alas . t
Volume = 24√5 . 20
Volume = 480 √5 cm²
Volume = 1.073,32 cm²