The hypotenuse is 39 because is opposite to the angle of 90 degrees.
So, angle A is given by
[tex]\measuredangle A=\sin ^{-1}\frac{7}{39}[/tex]Then, we have
[tex]\measuredangle A=\sin ^{-1}(0.17948)[/tex]which gives
[tex]\measuredangle A=10.339\text{ degre}es[/tex]Now, angle C is equal to 90 degrees and angle B is given by
[tex]\begin{gathered} \measuredangle B=\cos ^{-1}(\frac{7}{39}) \\ \measuredangle B=\cos ^{-1}(0.17948) \\ \measuredangle B=79.66\text{ degr}ees \end{gathered}[/tex]Therefore, the answer is
[tex]\begin{gathered} \measuredangle A=10.339\text{ degre}es \\ \measuredangle B=79.669\text{ degre}es \\ \measuredangle C=90\text{ degre}es \end{gathered}[/tex]