Jawabanmu

2014-05-12T22:16:32+07:00
Ao = 3 x 4 = 12 cm²
β = 2α
β = 2 x 0,00002 = 0,00004
A = Ao + Ao  β  ΔT
A= (12) + (12 x 0,00004 x (87-27)
A = 12 + ( 12 x 0,00004 x 40)
A = 12 + 0,0192
A = 12,0192 cm²