MathDB

2

Part of 2020 Nigerian Senior MO Round 2

Problems(1)

Menelaus theorem

Source: Nigeria Olympiad senior mathematics round 2 2020 problem 2

1/19/2020
Let DD be a point in the interior of ABCABC. Let BDBD and ACAC intersect at EE while CDCD and ABAB intersect at FF. Let EFEF intersect BCBC at GG. Let HH be an arbitrary point on ADAD. Let HFHF and BDBD intersect at II. Let HEHE and CDCD intersect at JJ . prove that GG,II and JJ are collinear
geometry