Five fourths of a right angle
A right angle is 90 degrees.
Five fourths is [tex]\sf \frac{5}{4} [/tex]
Five fourths OF A right triangle
[tex]\sf \frac{5}{4} [/tex] OF 90 degrees
Of means multiplication so:
[tex]\sf \frac{5}{4}\times 90 [/tex]
And that equals to 112.5
So your final answer is
[tex]\boxed{\bf{112.5~degrees}}[/tex]