Answer:
:D
Step-by-step explanation:
we know that
The formula of the surface area of the cone is equal to

where
SA is the surface area
r is the radius of the cone
l is the slant height
in this problem we have

Solve the formula for l

substitute the values

therefore
<u>the answer is</u>
The slant height is 
To round to the nearest tenth place you are going to round the last two digits of that, you should get 519.7