The sum of the angles is
[tex]\dfrac{3}{2}x+\dfrac{1}{2}x+x=3x[/tex]
The sum of the interior angles of a triangle is 90 degrees or [tex]\pi[/tex] radians. Assuming that these are the "two ways" the exercise is looking for, you can write
[tex]3x=90[/tex]
or
[tex]3x=\pi[/tex]
depending on whether you're using radians or not.
If you don't think that these are the "two ways" please let me know, and we'll try to figure something else out.
