Let X be the the intersection point between S and B
I assume you need surface area and volume
To get both you will need length SX
and to get surface area you will also need RS
\(tan30 = \frac{SX}{RX}\\\\ \frac{1}{\sqrt{3}}= \frac{SX}{12}\\\\ \frac{12}{\sqrt{3}}= SX\\\\ SX=4\sqrt{3}\;\; dm\\\\\)
\(cos30=\frac{RX}{RS}\\\\ \frac{\sqrt{3}}{2}=\frac{12}{RS}\\\\ \frac{2}{\sqrt{3}}=\frac{RS}{12}\\\\ \frac{24}{\sqrt{3}}=RS\\\\ RS=8\sqrt{3}\;\;dm\)
Can you take it from there?
If not just ask for more help :)
Oh you need to check my working too. I think it is right but I don't put too much effort into proof reading because I think that is mainly your job. If something doesn't make sense or you need more explanation, just let me know. :)