how do I calculate surface area of a cylinder 30 feet in diameter and 18 feet long?

Answer 1

You first need to work out the circumference of the circle, which is 2 x pi x 15. Then multiply the answer by 30. I've attached a link to help you find the value of pi.

I gather that the cylinder is open at each end. If not, you instead need to work out the 'area' of the circle at each end by using pi x (r x r). Add the two circles together and multiply it by the length.

Answer 2

SA = 2pi r^2 + 2pi rh

radius = 1/2 diameter = 15 feet
height = 18 feet.

You have the top and bottom that are 2 circles with area
A = 2 pi (15)^2

then think of the side as a rectangle (like a soup can label)A = h* l with height h and length=circumference
Lateral surface area = 2 pi r h
A = 2 pi (15)(18)

SURFACE AREA = (450pi + 540 pi)
= 990 pi square feet

aprroximately = to 3110.177 square feet

Answer 3

D = 30
L = 18

Circumference of a circle is Pi x D
Circ = 30 x Pi
Area of the cylinder wall = 30 x Pi x 18 = 540 Pi

Area of ends = Pi x R^2
2 ends so total area of ends = 2 x Pi x R^2
R = D/2 = 15
Area = 2 x Pi x 15^2 = 450 Pi

Total area therefore = 450 Pi + 540Pi = 990 Pi

Answer 4

pi x diameter x height gives you the area of the cylinder part and if you want to include the ends as well then it's add 2 x pi x radius^2

Answer 5

quilasheila is corrrect

Surface area of cylinder => 2.pi.r(r+h)
r = diameter/2 => 30/2 =>15
h = 18
pi=3.14 (approx)

2.pi.15(18+15)
30.pi(33)
990.pi
=> 3108.6 feet.

Answer 6

first you need to find the perimeter of the circle
=2 pi 9= 18 pi
the surface area of the side of cylinder is the perimeter of the circle x height= 18 pi x 30= 540 pi
now you need to find the area of the two circles= 2x(pi9^2)
=162 pi
the total surface area= 540 pi+ 162pi= 702 pi

Answer 7

d = 2r =30 ft. r =30/2=15 h = 18 ft.
surface area = 2(3.14)(r + h ) square ft.
=6.26(15 +18)
=6.26(33)
=206.58 square ft.

Answer 8

SA = 2 π r² + π.r.h ----- (r = 15 ft , h = 18 ft)
SA = 2 π r (r + h)
SA = 30 π (33) ft²
SA = 3110 ft² (to nearest whole number)