5th GRADE MATH
posted by Please Help .
Jamie is forming a cylinder out of two circles and a rectangle. The area of each circle is 4 pi. The diameter of each circle is 4 cm. The height of the rectangle is 6 cm.
Which shows how Jamie could calculate the surface area of the cylinder?
a. 2(4pi)+ 6(4pi)
b. 2(4pi)+ 6(4)
c. 4pi x 4 x 6 pi
d. 4pi x 4 x 6
I chose b the first time. I chose d the second time and was told that I had the wrong answer both times. Will you please explain? Thanks

Visualize a can, cut off the top and bottom,
you now have a hollow cylinder.
Suppose you take snippers and make a vertical cut and spread out the hollow form.
Would you not get a rectangle whose height is the height of the original can and whose length is the circumference of the circle?
looks like a) to me 
u r right b is the corrct ans.