Answer
$\alpha=29^{\circ}$
$\beta=61^{\circ}$
Work Step by Step
$\sin\alpha=\frac{12}{25}$
$\alpha=\sin^{-1}\frac{12}{25}$
$\alpha\approx29^{\circ}$
Sum of interior angles of a triangle $= 180^{\circ}$
$90^{\circ} + \alpha + \beta = 180^{\circ}$
$90^{\circ} + 29^{\circ} + \beta \approx 180^{\circ}$
$\beta\approx61^{\circ}$