Question

A right circular cylinder has a total surface area of 112pie. If the height of the cylinder is 10, find the diameter of the base.

Answer 1

haha you called it 112"pie". that's funny.

formula is circumference * height + 2 (area of circle)

that works out to 2pi*r*h + 2pi*r^2 = 112pi
You have h so you can plug that in.
20pi*r + 2pi*r^2 = 112pi
cancel out the pi.
20r + 2r^2=112
move stuff over.
2r^2 + 20r - 112 = 0
divide.
r^2 + 10r - 56 = 0
factor.
(r+14)(r-4)
-14 and 4 are the answers, only positive number works, so r = 4
d = 8

Answer 2

hey i had answered u already diameter is approximately equal to 83 mm and exactly it is 82.8 mm

Answer 3

I got that one Sheg but it was for a different question. Thank You!