Here, we seek the angle adjacent to one of the given sides' length.
When given the hypothenuse and the adjacent lengths, we employ the SOH CAH TOA formulae.
This gives us:
[tex]\begin{gathered} \cos \theta=\frac{adjacent}{hypothenuse}\text{ | Notice the first letters were used for the acronym} \\ \text{Therefore, }\theta=\cos ^{-1}\frac{adjacent}{hypothenuse} \end{gathered}[/tex]
Where
adjacent = 15
Hypothenuse = 34
Employing back into the formulae, we have:
[tex]\begin{gathered} \theta=\cos ^{-1}(\frac{15}{34}) \\ \theta=63.82^o \end{gathered}[/tex]
The missing angle is approximately 64 degrees
