rite triangel
side1=diagonal-1
diagonal=3*side2 +4, so side2=(d-4)/3
d^2=side1^2 +side2^2
d^2=(d-1)^2 +(d-4)^2 /9
d^2=d^2 -2d +1 +d^2/9 -8d/9 +16/9
0=-2d -8d/9 +1 +d^2 /9 +16/9
or d^2 -18d -8d +9 +16=0
d^2 -26d +25=0
d=25 or d=1
tri d=25, then side1=24, side2=(d-4)/3=21/3=7
7, 24, 25
thats on mi list av kommon pythagorean tripels