Question

Jika luas permukaan balok 108 cm²,tinggi 4cm ,dan lebar 3 cm.tentukan
a).panjang rusuk balok
b).panjang kawat yang dibutuhkan

Answer 1

A. Lp = 2 (pl+pt+lt)
        = 2(3p+4p+4.3)
        = 2(7p+12)
   108= 14p+24
14p+24= 108
     14p=108-24
      p= 84/14
      p=6cm
b. p. kawat= 4 (p+l+t)
                = 4 (6+3+4)
                = 4x13
                = 52 cm

Answer 2

L = 2(p.l+p.t+l.t)
108 = 2(p.3+p.4+3.4)
108 = 2(3p+4p+12)
108/2 = 7p+12
54 = 7p+12
7p = 54-12
7p = 42
p   = 42/7
p   = 6 cm

Kawat yg dibutuhkan
= 4(p+l+t)
= 4(6+3+4)
= 4(13)
= 52 cm