Right Cylinder: Surface Area
How to find the surface area of a right cylinder: definition, formula, 1 example, and its solution.
Cylinder
A cylinder is a 3D figure
that has
a pair of circle bases
and a lateral face.
The bases are congruent and parallel.
Right Cylinder
A right cylinder is a cylinder
whose centers of the bases
are the endpoints of the height.
Formula
A = 2⋅πr2 + 2πr⋅h
A: Surface area of a cylinder
r: Radius of the base circle
h: Height
2πr2 are the two base areas (= circle).
Circle: Area
2πr⋅h is the lateral area.
(2πr is the circumference of the base circle.)
Circle: Circumference
Exampler = 4, h = 9, A = ?
The radius of the base is 4.
So r = 4.
The height h is 9.
Then the surface area A
is equal to,
the two base areas, 2⋅π⋅42
times,
the lateral area,
2π⋅4 times 9.
So A = 2⋅π⋅42 + 2π⋅4⋅9.
2⋅π = 2π
42 = 16
4⋅9 = 36
2π⋅16 = 32π
+2π⋅36 = +72π
32 + 72 = 104
So the surface area of the right cylinder is
104π.