= Sertakan cara ya =

Cari tinggi balok
misal x = tinggi balok

6²+4²+x² = (2√17)²
36+16+x² = 68
52+x² = 68
x² = 16
x = 4

Luas permukaan balok
= 2(pl+pt+lt)
= 2(24+24+16)
= 2(64)
= 128 cm²