Answer: The answer here is 45* because all you need to do is 180-72-63 then BAM you get your answer :)
The sum of all angles in any triangle is 180°.
[tex]\beta=180-(\alpha+\gamma)[/tex]
[tex]\beta=180-(72+63)[/tex]
[tex]\beta=180-135=\boxed{45}[/tex]
