Question 118452
Given: (triangle) {{{EFG}}} is a right traingle
       (angle) {{{G}}} is a right angle
Prove: mesure of angle {{{E < 90°}}}

The sum of the three angles of any triangle is {{{180}}} degrees, so

{{{E + F + G = 180°}}}

since {{{G = 90°}}}...=>.... the sum of the other two angles is also {{{90°}}}, or 

{{{E + F = 90°}}}...=>...{{{E}}} must be less then {{{90°}}}, or

{{{E < 90°}}}