carilah luas permukaan balok dengan panjang sisi berikut: a. p = 25 cm, l = 12 cm, t = 10 cm b. p = 5 dm, l = 45 cm, t = 5 dm c. p = 3,2 m, l = 18 cm, t = 65 cm

a. Lp = 2(p . l) + 2(p . t) + 2(l . t)
= 2(25 . 12) + 2(25 . 10) + 2(12 . 10)
= 2(300) + 2(250) + 2(120)
= 600 + 500 + 240
= 1.340 cm²

b. Lp = 2(p . l) + 2(p . t) + 2(l . t)
= 2(50 . 45) + 2(50 . 50) + 2(45 . 50)
= 2(2250) + 2(2500) + 2(2250)
= 4500 + 5000 + 4500
= 14.000 cm²

c. Lp = 2(p . l) + 2(p . t) + 2(l . t)
= 2(320 . 18) + 2(320. 65) + 2(18 . 65)
= 2(5.760) + 2(20.800) + 2(1.170)
= 11.520 + 41.600 + 2.340
= 55.460 cm²

A. Luas permukaan = 2(p.l + p.t + l.t)
= 2 × (25.12)+(25.10)+(12.10)
= 2 × (300+250+120)
= 2 × 670
= 1.340 cm²
B. p = 5 dm = 50 cm
t = 5 dm = 50 cm
Luas permukaan = 2(p.l + p.t + l.t)
= 2 × (50.45)+(50.50)+(45.50)
= 2 × (2.250+2.500+2.250)
= 2 × 7000
= 14.000 cm²
C. p = 3.2 m = 320 cm
Luas permukaan = 2(p.l + p.t + l.t)
= 2 × (320.18)+(320.65)+(18.65)
= 2 × (5.760+20.800+1.170)
= 2 × 27.730
= 55.460 cm²