Question 473725
Surface Area of sphere is {{{4*pi*r^2}}}
Radius is exactly half the diameter.
Given: diameter is 4 --> {{{(1/2)*4 = 2}}}
So the radius of the sphere is 2.
Now substitute this value into general formula
{{{4*pi*2^2 = 4*pi*4 = 16*pi}}}
Therefore, surface area is 16pi sq.cm.