Chapter 12.10, Problem 26HP

To determine

To calculate: To determine how can we find the surface area of a cone if diameter of base and slant height is given.

Answer to Problem 26HP

By finding radius of the cone with the help of diameters , we can apply the formula for surface area of the cone.

Explanation of Solution

Given information:

The given information is, Diameter and slant height of cone are given.

Formula used:

Surface area $=2(lb+bh+lh)$

Calculation:

Let diameter of cone be d and slant height is l.

Now, using $r=\frac{d}{2}$ , we can change the formula for surface area of cone as:

  $\begin{array}{l}surfacearea=\pi r(r+l)\\ =\pi \frac{d}{2}(\frac{d}{2}+l)\\ =\frac{\pi d}{2}(d+2l)\end{array}$