Nine point circle, passing through midopints of sides DEF, , feet of altitudes J, G,N , and midpoints K,L,M of lines joining orthocentre H to the vertices A, B, C The centre P of this nine point circle bisects the segment HO joining the orthocentre to the circumcentre O, and the centroid Q divides the same segment HO in the ration 2:1.
have fun pulling A, B, C and seeing all the various points move