mathematics
posted by Matt on .
One of two numbers that can be both the area and perimeter of a triangle whose side lengths are a Pythagorean triple?

It is here...
http://www.mcs.surrey.ac.uk/Personal/R.Knott/Pythag/pythag.html#patterns 
One of two numbers that can be both the area and perimeter of a triangle whose side lengths are a Pythagorean triple.
The 51213 Pythagorean Triple triangle has an area and perimeter of 30.