There are 6 trees on the shortest side, that is, there are 5 intervals.

It is known that the second side has 12 intervals and 13 trees.

The third side has 13 intervals, and 14 trees.

Subtract one from each corner.

That is, the total * * * is 6+ 13+ 14-3=30.

Plant 30 trees on the side of each right triangle.

Four triangles * * * need to plant 4X30= 120 trees.