Answer to Student's Question on Right Angle Triangle

[roni1]

A student ask me the question:
Why the other angles in Right angle triangle can't be more than 90 degrees?
I want to answer him correctly to the question, What Should I Say to Him?

 

[MarkFL]

The sum of the interior angles in a triangle is $180^{\circ}$. Given that one angle is $90^{\circ}$ this leaves $90^{\circ}$ for the sum of the other two angles, which means that for either of the other angles, they must be greater than $0^{\circ}$ and less than $90^{\circ}$.