Assuming it's a quarter circle corner tank:
Volume:
1/4 * 3.14 * (3ft)squared * 2ft = 14.14 cubic feet = 105.7745455 US gallon
Surface area:
1/4 * 3.14 * (3ft)squared = 7.05 sq. ft. = 1017 sq. inches
By the volume calculation, you could have 105 inches of fish.
By the surface area calculation, you could have 85 inches of fish.
Someone else can do the math on how much fish you have right now, but when it comes right down to it, if your parameters are good and your filtration is keeping up and your fish are not having territory issues, then you're probably ok.