Formula: A2 = A1(1 + βθ)
where β = The area expansivity
θ = Change in temperature.
β = 2α
where α = linear expansivity of the body.
⇒ β = 2 x 0.000017
= 0.000034 K−1
∴ A2 = 100 (1 + (0.000034 x 70))
= 100(1 + 0.00238)
= 100(1.00238)
= 100.238 cm2
= 100.24 cm2 (to 2 d.p)
