Question 1157788

Could you help me find the total surface area of the following cone? The answer must be left in terms of pi. The length is 4cm. Radius is 3cm. 
<pre>That other person, AS USUAL, is <b><u>WRONG</b></u>!! The total surface area is <b><u>NOT</b></u> {{{20pi}}}.
Surface area of cone = Area of circular base + Lateral Surface Area, or {{{pi * r^2 + pi * rl}}}, with r being radius, and l being slant height.
With r (radius) being 3 cm, if the height is 4 cm, then this represents a 3-4-5 right-triangle with a SLANT height (l) of 5 cm
We then have: {{{highlight_green(matrix(1,7, pi * r^2 + pi * rl, "=", pi * 3^2 + pi * 3(5), "=", 9pi + 15pi, "=", 24pi))}}}