First, Look at the attached picture as a reference.
Now, using Pythagoras theorem,
[tex]AC^2=AB^2+BC^2 \\\\AC=\sqrt{AB^2+BC^2 }\\\\AC=\sqrt{10^2+(10\sqrt3)^2}\\\\ AC = \sqrt{100+300}\\\\AC=\sqrt{400}\\\\AC=20~in.[/tex]
Now, lets find the elevation of the sun.
[tex]tan\theta = \frac{AB}{BC} \\\\ tan\theta = \frac{10}{10\sqrt3} \\\\ \theta = tan^{-1} \left(\frac{10}{10\sqrt3}\right) \\\\ \boxed{\theta = 30 \°}[/tex]
∴ The elevation of the sun is 30°
