A wooden article was made by scooping out a hemisphere from each side of a solid cylinder as shown in the figure. If the height of the cylinder is 12 cm and its base is of radius 4.2 cm, find the total surface area of the article. (Take π = $\dfrac{22}{7}$).

Given,

Height of cylinder (h) = 12 cm

Radius of base (r) = 4.2 cm

Total surface area of the article (T) = Curved surface area of the cylinder + 2 surface area of a hemisphere

= 2πrh + 2(2πr²)

Substituting values we get :

$T = 2 \times \dfrac{22}{7} \times 4.2 \times 12 + 4 \times \dfrac{22}{7} \times (4.2)^2 \\[1em] = 44 \times 0.6 \times 12 + 88 \times 0.6\times 4.2 \\[1em] = 316.8 + 221.76 \\[1em] = 538.56 \text{ cm}^2.$

Hence, total surface area of the article = 538.56 cm².