Page 149 - BS 8 Matematika 2

No. Prisma Luas permukaan prisma

Luas = 2 × I + II + III + IV + V
8 cm = 2 × (8 × 6) + (6 × 40)
6 cm I 6 cm + (8 × 40) + (6 × 40) +
(8 × 40)
6 cm 8 cm 6 cm 8 cm
= 2 × (8 × 6) + (6 + 8 + 6
+ 8) × 40
40 cm II III IV V 40 cm × 40
2. = 2 × (8 × 6) + 2 × (8 + 6)

= 2 × (48) + 2 × (14) × 40
6 cm 8 cm 6 cm 8 cm = 96 + 28 × 40

6 cm I 6 cm = 96 + 1.120
= 1.216
8 cm
Jadi, luasnya adalah 1.216 cm 2.

Luas = 2 × I + II + III + IV + V
+ VI + VII
10 cm
10 cm 10 cm = 2 × I + II + II + II + II
I + II + II
10 cm
= 2 × I + 6 × II
10 cm 10 cm 10 cm
1
= 2 × (6 × × 10 × 5 3)
2
II III IV V VI VII 30 cm
+ 6 × (10 × 30)
30 cm
= 2 × (150 3) + 6 × (300)
10 cm 10 cm 10 cm
3.
10 cm = 300 3 + 1.800
I Jadi, luasnya adalah (300 3 +
10 cm 10 cm
10 cm 1.800) cm 2.

Keterangan:
10 cm10 cm 10 cm 10 cm t = 10 − 5 2
2
t
−
= 100 25
10 cm
10 cm = 75
10 cm
= 5 3

140 Kelas VIII SMP/MTs Semester II