Are the coordinates of three points on the map.

Need to find the coordinates of the center described the resulting triangle around the circumference.

Classic geometrical solution through the normals are not perfect, no polynomial conversion, to perform the last really do not want (and to be honest it is not clear how to produce it).

Are there any ideas of a simpler way to find the center?

the calculation is carried out in php

here is a concrete example. The necessary three points marked with crosses, the fourth cross is the center of a circle obtained when using the classical approach from geometry, the perpendiculars through

the task as a whole (real estate theme):

Yandex maps does not know how to determine the intersection of (

We came up with is this: have a database of houses (in the streets) and the coordinates of these homes. Need to find the intersection of two intersecting streets obviously.

Select all the houses in these streets and looking for the house, located for example within 200 metres from each other (but on different streets, but the EU, i.e. each house from one street to compare with each house on a different street). In fact the picture that is what is depicted (different street = different icons). Next, it's necessary to determine the approximate region in which it is specified in the Declaration as the "crossroads of streets of Tukhachevsky and Magnitogorsk". Approximate area = circumference