The area of the base of a closed cylinder is 1386 cm². If the height of the cylinder is 20 cm, then what is the total surface area of the cylinder? [Use π = $\frac{22}{7}$]

5412 cm²

We know that,

Total surface area of base of the cylinder = 2πr(r + h)

We have,

The area of closed cylinder = 1386 cm^2.

Height = 20 cm.

According to the question,

πr² = 1386

= r² = 1386 × \(\frac{7}{22}\)

= r = 21

Total surface area = 2 × \(\frac{22}{7}\) × 21 × (20 + 21) = 2 × 66 × 41 = 5412