Question

Alex designed the model of a cylindrical water tank to be installed in a park. The model has a radius of 4 cm and a height of 12 cm. The dimensions of the actual water tanks that will be installed in the park are 5 times larger than the model. The total surface area of the actual water tanks, rounded to the nearest whole number, is _________ cm2. Use for pi.

Answer 1

@Calcmathlete

Answer 2

Do you remember the formula for the surface area of a cylinder?
\[SA_{Cylinder} = 2πr^2 + 2πrh\]

Answer 3

yeah so plug them in?

Answer 4

Yes. Tell me what you get in exact terms of π. Then I'll show you the next step.

Answer 5

401.92

Answer 6

but its sais use 22/7

Answer 7

I said in exact terms of π, so leave π as a variable for now. We'll plug it in later to make it simpler. You should've gotten 128π Now, let's set up a proportion.
\[\frac{25}{1} = \frac{x}{128π}\]Solve for x.

Answer 8

3200pi

Answer 9

Alright. Now use 22/7 and plug it in for π.

Answer 10

10057.142857

Answer 11

Yup :)