Question

1413 square metres o paint was used to paint a closed cylindrical tank of radius 10 metres. What is the height of the cylindrical tank?

Answer 1

Solution

Given the question in the image, the following are the solution steps to answer the question.

STEP 1: Write the given measures

$r=10m,h=?,TSA=1413m^2$

STEP 2: Write the formula for the total surface area of a cylinder

$TSA=2\pi r(r+h)$

STEP 3: Get the measure of the height

By substitution,

$\begin{gathered} 1413=2\pi(10)(10+h) \\ Divide\text{ both sides by 20pi} \\ \frac{1413}{20\pi}=10+h \\ 22.48859346=10+h \\ h=22.48859346-10 \\ h=12.48859346 \\ h\approx12.49m \end{gathered}$

Hence, the height of the cylindrical tank is approximately 12.49m