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 = $\frac{22}{7}$]
Answer & explanation
Correct answer: option 1
We know that,
Total surface area of base of the cylinder = 2πr(r + h)
We have,
The area of closed cylinder = 1386 cm2.
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