Question 175801
Call the first angle x.  Then the second angle can be represented by 2x.  Since the third is the sum of the other two, the third can be represented by x+2x=3x.  Since the sum of the angles in a triangle is 180 degrees, we have that
{{{x+2x+3x=180}}}
{{{6x=180}}}
{{{x=30}}}
Thus the first angle is 30 degrees, the second angle is 60 degrees, and the third angle is 90 degrees.