Answer
sin α=$\frac{3}{\sqrt {13}}$
sin β= $\frac{2}{\sqrt {13}}$
Work Step by Step
In given right triangle, applying Pythagorean theorem-
$(\sqrt {13})^{2} = b^{2} + 3^{2}$
Therefore-
$b^{2} = (\sqrt {13})^{2} - 3^{2}$ = 13 - 9 = 4
a = $\sqrt {4}$ = 2
sin α=$\frac{opposite}{hypotenuse}=\frac{3}{\sqrt {13}}$
sin β=$\frac{opposite}{hypotenuse}=\frac{b}{\sqrt {13}}$ = $\frac{2}{\sqrt {13}}$