It appears that you correctly used the Pythagorean Theorem to find $\displaystyle{p}=\sqrt{{51}}\usepackage{cmbright}\Huge\$ , but you found the value of $\displaystyle{\tan{{P}}}\usepackage{cmbright}\Huge\$ . Use the definition of sine:

$\displaystyle\text{sine}=\frac{\text{opposite}}{\text{hypotenuse}}\usepackage{cmbright}\Huge\$