please elaborate the incentre circumcentre and orthocentre. and explain some formula related to it.

Circumcentre is the points of intersection of the medians drawn at each vertex of the triangle.

Orthocentre is the point of intersection of all the three perpendicular bisectors of the triangle.

and

Incentre is the triangle focus, a point characterized for any triangle in a way that is free of the triangle's situation or scale. The incenter might be proportionately characterized as the point where the interior edge bisectors of the triangle cross, as the point equidistant from the triangle's sides, as the intersection purpose of the average hub and deepest purpose of the grassfire change of the triangle, and as the middle purpose of the recorded hover of the triangle.