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15th Annual Harvard-MIT Mathematics Tournament #0jc0

15th Annual Harvard-MIT Mathematics TournamentHard

From module Regular Polygons

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Understand the scale
Scale 0.5: Easiest math competition problems, often solvable even for early middle school students without experience. 1: Problems strictly for beginners, often at a moderate middle school level. 1.5: Problems for stronger beginner students, on the level of the middling problems in most middle school contests. 2: For motivated beginners, harder questions from the previous categories. 2.5: More advanced beginner problems, hardest questions from previous categories. 3: Early intermediate problems that require more creative thinking. 3.5: Tougher early intermediate problems that consistently stretch into higher-level creative thinking or conceptual knowledge. 4: Intermediate-level problems. 4.5: Upper intermediate problems approaching the upper bound for non-invitational sprint math competitions. 5: More difficult AIME problems or simple proof-based Olympiad-style problems. 6: High-level AIME-styled questions or introductory Olympiad-level questions. 7: Tougher Olympiad-level questions, may require more technical knowledge. 8: High-level Olympiad-level questions. 9: Expert Olympiad-level questions. 9.5: The hardest problems appearing on Olympiads which the strongest students could reasonably solve. 10: Historically notorious problems, generally unsuitable for even very hard competitions because they are exceedingly tedious, long, and difficult.
QuadrilateralsConstructions and loci

Problem

Problem:

Let rectangle ABCDA B C D have lengths AB=20A B = 20 and BC=12B C = 12. Extend ray BCB C to ZZ such that CZ=18C Z = 18. Let EE be the point in the interior of ABCDA B C D such that the perpendicular distance from EE to AB‾\overline{A B} is 66 and the perpendicular distance from EE to AD‾\overline{A D} is 66. Let line EZE Z intersect ABA B at XX and CDC D at YY. Find the area of quadrilateral AXYDA X Y D.

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