One way to set up a correct equation is to use the definition of sine:

$\displaystyle{{\sin{{65}}}}^{\circ}=\frac{{14}}{{x}}\usepackage{cmbright}\Huge\$

Solve this equation for x:

$\displaystyle{x}\cdot{{\sin{{65}}}}^{\circ}={14}\usepackage{cmbright}\Huge\$

$\displaystyle{x}=\frac{{14}}{{{\sin{{65}}}}^{\circ}}\approx\frac{{14}}{{0.90631}}\approx{15.447}\usepackage{cmbright}\Huge\$

This rounds to 15.45.