a cylinder is formed by first tapping together the opposite edges of a rectangular piece of paper that is 11 inches long and 8.5 inches wide. if the height of the completed cylinder 8.5 what is its volume?use 3.14 for pie

4 answers

First find the diameter.

Circumference = pi * d
11 = 3.14d
11/3.14 = d
3.5 = d

So the radius = 1.75

Then use this formula for the volume of a cylinder.

V = pi * r^2 * h

http://www.mathsteacher.com.au/year9/ch14_measurement/18_cylinder/cylinder.htm
i am sorry ms. sue i still don't get it could you please give me an explanation for 'dummies' thank you
The circumference is formed by the 11" piece of paper.

We need to find the diameter.


Circumference = pi * d
11 = 3.14d
11/3.14 = d
3.5 = d

The radius is half the diameter -- 1.75

Now we can use the formula for volume.

V = pi * r^2 * h
V = 3.14 * 1.75^2 * 8.5
V = 3.14 * 3.1 * 8.5

Now multiply those three numbers to find the volume.

Also see the website I posted.
Maybe you don't get it because you confused "tapping" in your question with "taping".

The ends are taped together. The 11 inch width of the paper becomes the circumference of the circular base area of the cylinder.

What don't you understand in MsSue's explanation? Multiply the last three numbers in her answer to get the volume.