Triangle-shaped Belly Button After Hernia Surgery

Your belly button certainly looks triangular at this time, but there is still evidence of ongoing healing; there's clearly skin discoloration consistent with bruising and your skin and soft tissue appear swollen. As the swelling and bruising go away, it's possible that your belly button may develop a more normal shape.
If, at least 6 months after your umbilical hernia repair, you still have an abnormally-shaped belly button, you' may be a candidate for an umbilicoplasty. This can often be performed under local anesthesia. It would entail making new incisions around the stalk of the belly button and re-insetting it to the abdominal wall skin, to give you more of an oval or round belly button.
Best of luck!

I share your concern but time is a great healer.
For the time being, the tissue is still healing and the process will go on for 6-8 months. To influence scarring, if the umbilicus would let you, you may want to see if you can put a round marble in there which will essentially stent the walls and direct the walls to scar in a more circular fashion.
If the result is not to your liking in 6-8 months, I would consult a plastic surgeon (check www.PlasticSurgery.org for listing).
Dr. P. Aldea

Usually, hernia surgery is on the lower half of the belly button. This area is sometimes fixed by the scar for a period of time. Ask your surgeon when you can start to massage the scar. Massage will usually help this change resolve.