You are looking for something called the centroid of the triangle
it is found like this:
the triangle
Side 1: Merry go round and Swing we must bisect this side and draw a like from the bisection point to the alternate angle (see saw),
Side 2 and 3 : Repeat this with all sides.
the point where all line meet inside the triangle is called the centroid and is the same distance from all pieces in the park.