Question

Find the height of a closed cylinder of radius 7cm and surface area 1672sq.cm

Answer 1

Answer:

Total Surface Area =

$2\pi \: r( \: r + \: h \: )$

1672 = 2× 22/7 × 7 ( 7 + h)

1672 = 44 (7+h)

1672 = 308 + 44h

1672 - 308 = 44h

1364 = 44h

1364/44 = h

31 = h

Therefore, height of the cylinder is 31 cm.

Answer 2

Answer:

The height of the cylinder is 31 cm.

Step-by-step explanation:

Th surface area of a cylinder is:

$SA=2\pi rh+2\pi r^{2}$

Given:

SA = 1672 sq.cm

r = 7 cm

Compute the value of height (h) as follows:

$SA=2\pi rh+2\pi r^{2}\\1672=(2\times\frac{22}{7}\times7\times h)+(2\times\frac{22}{7}\times7^{2})\\1672-308=44h\\h=\frac{1364}{44}\\=31$

Thus, the height of the cylinder is 31 cm.