--- id: 5900f4751000cf542c50ff87 title: 'Problem 264: Triangle Centres' challengeType: 5 forumTopicId: 301913 dashedName: problem-264-triangle-centres --- # --description-- Consider all the triangles having: - All their vertices on lattice points. - Circumcentre at the origin O. - Orthocentre at the point H(5, 0). There are nine such triangles having a $\text{perimeter} ≤ 50$. Listed and shown in ascending order of their perimeter, they are:
A(-4, 3), B(5, 0), C(4, -3) A(4, 3), B(5, 0), C(-4, -3) A(-3, 4), B(5, 0), C(3, -4) A(3, 4), B(5, 0), C(-3, -4) A(0, 5), B(5, 0), C(0, -5) A(1, 8), B(8, -1), C(-4, -7) A(8, 1), B(1, -8), C(-4, 7) A(2, 9), B(9, -2), C(-6, -7) A(9, 2), B(2, -9), C(-6, 7) |