Ok so all the angles in any triangle always add up to 180 degrees.
So we know that in this case one angle is 90 degrees, one is 2x+15 degrees and one is x degrees.
90+2x+15+x=180.
Solve for x.
90+3x+15=180.
105+3x=180.
3x=75
x=25
2(25)+15=50+15=65.
So one angle is 65 degrees, one is 25 degrees and one is 90 degrees
