The formula to calculate the surface area of a cone is given by
![SA=pi*r^2+pi*r*l](https://img.qammunity.org/qa-images/2023/formulas/mathematics/college/l3g4ft0dfddfn2jvg2at.png)
where
r=16/2=8 in ----> the radius is half the diameter
l=18 in ----> slant height
substitute given values
![\begin{gathered} SA=pi*8^2+pi*8*18 \\ SA=64pi+144pi \\ SA=208pi\text{ in}^2 \end{gathered}](https://img.qammunity.org/qa-images/2023/formulas/mathematics/college/msas0bhfftmvodsrf4cv.png)
The surface area is 208pi square inches
Problem N 9
Find out the height of the cone
Applying the Pythagorean Theorem
![\begin{gathered} l^2=h^2+r^2 \\ 18^2=h^2+8^2 \\ h^2=18^2-8^2 \\ h^2=260 \\ h=√(260) \\ h=16.1\text{ in} \end{gathered}](https://img.qammunity.org/qa-images/2023/formulas/mathematics/college/8jt7n4k1bh9slldycoi4.png)
The answer is option B