The formula to calculate the surface area of a cone is given by
[tex]SA=pi*r^2+pi*r*l[/tex]
where
r=16/2=8 in ----> the radius is half the diameter
l=18 in ----> slant height
substitute given values
[tex]\begin{gathered} SA=pi*8^2+pi*8*18 \\ SA=64pi+144pi \\ SA=208pi\text{ in}^2 \end{gathered}[/tex]
The surface area is 208pi square inches
Problem N 9
Find out the height of the cone
Applying the Pythagorean Theorem
[tex]\begin{gathered} l^2=h^2+r^2 \\ 18^2=h^2+8^2 \\ h^2=18^2-8^2 \\ h^2=260 \\ h=\sqrt{260} \\ h=16.1\text{ in} \end{gathered}[/tex]
The answer is option B
