The radius of cylinder is 7 cm and height is 11 cm. The total surface area of cylinder will be:
Answer & explanation
Correct answer: option 2
The correct answer is Option (2) → 792 cm2
The total surface area of a closed cylinder is its curved surface plus its two circular ends: \(2\pi rh+2\pi r^{2}=2\pi r(r+h)\). The curved surface, opened out, is a rectangle as long as the base’s circumference \(2\pi r\) and as tall as the cylinder.
Radius \(r=7\) cm and height \(h=11\) cm, so \(r+h=18\) cm
Total surface area: \(\displaystyle 2\times\frac{22}{7}\times7\times18=44\times18\)
Total surface area \(=792\,\mathrm{cm^{2}}\)