pairs of opposite sides of the hexagon ADEGBZ are collinear. Lemmas XV and XVII are that, if the point M is determined as the intersection of HK and BG, then the points A, M, and D are collinear. That is, the points of intersection of the pairs of opposite sides of the hexagon BEKHZG are collinear. Notes References External links Pappus's hexagon theorem at cut-the-knot Dual to Pappus's hexagon theorem at cut-the-knot Pappus’s Theorem: Nine proofs and three variations Theorems in projective geometry Euclidean plane geometry Articles containing proofs