We have the following:
We can calculate this by means of the following proportion
[tex]\frac{SA}{SR}=\frac{SC}{ST}[/tex]
replacing:
[tex]\begin{gathered} \frac{SA}{10}=\frac{4}{4+4} \\ SA=\frac{10\cdot4}{8} \\ SA=5 \end{gathered}[/tex]
Therefore, SA is equal a 5
