1974 AMC 12 Problem 5
Attempt Problem 5 of the 1974 AMC 12 below, then check your answer against the professionally curated solution from LIVE by Po-Shen Loh. You can also try the full timed exam, view all 1974 AMC 12 solutions, or check the answer key.
All problems are used with official legal permission of the Mathematical Association of America (MAA).
5.
Given a quadrilateral inscribed in a circle with side extended beyond to point if and find
Answer: B
Small hint:
Opposite angles of a cyclic quadrilateral are supplementary
Big hint:
The desired exterior angle is also supplementary to
Solution:
Because is cyclic, Since extends as well. Hence The given angle is unnecessary.
Therefore, the correct answer is B.
Problem 5 in other years
- 1950 AMC 12
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