The surface area of a cylinder is twice the area of the circle plus the area of the rectangle that makes the curved face.
Area of circle = (pi)r2
Area of rectangle = hc (height x circumference)
Circumference = 2(pi)r so hc = 2(pi)rh
Therefore the total surface area (A) is 2(pi)r2 + 2(pi)rh
To find r:
A = 2(pi)r2 + 2(pi)rh
2(pi)r2 + 2(pi)hr - A = 0
r = -b+-sqrt(b2 - 4ac)/2a
r = -2(pi)h+-sqrt((2(pi)h)2 - 4 x 2(pi) x - A)/4(pi)
r = -2(pi)h+-sqrt((4(pi)2h2 + 8A(pi))/4(pi)
A worked example:
A = 100 cm and h = 10 cm
r = -20(pi)+-sqrt(400(pi)2 + 800(pi))/4(pi)
r = -20(pi)+-sqrt(6461...)/4(pi)
r = -20(pi)+-80.../4(pi)
r = -11.396 cm or 1.397 cm, as length cannot be negative, r = 1.397 cm (3dp)
Note: sometimes both answers will be positive so both may be correct. Therefore still work out the positive square root.
Entire surface area of a cylinder = (2*pi*radius^2)+(circumference*height) If you are given the circumference then radius = circumference/2*pi
The answer depends on what information you are given: volume and height, or surface area and height, etc.
The answer depends on what information you are given: volume and radius or diameter, or surface area and radius, etc.
2(pi)(r)(h)=the area of the curved surface
You cannot. You need to know the height as well. If you know the height, the surface area, A is given by A = 2*Ï€*r2 + 2*Ï€*r*h where r is the radius and h the height.
Entire surface area of a cylinder = (2*pi*radius^2)+(circumference*height) If you are given the circumference then radius = circumference/2*pi
The answer depends on what information you are given: volume and height, or surface area and height, etc.
The radius of a cylinder given only the height could be anything you like.
The answer depends on what information you are given: volume and radius or diameter, or surface area and radius, etc.
2(pi)(r)(h)=the area of the curved surface
The radius IS given, since height of hemisphere = radius of hemisphere!
You cannot. You need to know the height as well. If you know the height, the surface area, A is given by A = 2*Ï€*r2 + 2*Ï€*r*h where r is the radius and h the height.
That will depend on its height which has not been given but the volume of a cylinder is pi*radius squared*height.
Not enough information. For a given radius, the height might be anything.
Given what??? I'd probably measure it
That depends on its height which has not been given
Since the formula for the volume of a cylinder is PI time the radius squared times the height we can calculate the height from the other two values. The height is the volume divide by PI times the radius squared.