The required equation of the surface area of the cylinder is
<u>Solution:</u>
Let "r" be the radius of cylinder and "h" be the height.
Formula for surface area is:
where is surface of two bases of cylinder and is surface of mantle.
From the given, the height of the gift box is three times the radius, i.e
On substituting the given values in the formula we get,
On multiplying inside the brackets we get,
Hence, the required equation is