Question 19862
the largest angle > the second largest angle
1/3 of the largest angle = 1/2 the second largest angle 
So the if largest angle is 90, and 1/3 of 90 is 30, then the smallest angle would be 30.
And because 1/3 of the largest angle = 1/2 of the second largest angle, the second largest angle has to be 60.  

Largest angle = 90
second largest angle = 60
smallest angle = 30  

Hope I could help.