Difference between revisions of "2021 AMC 12B Problems/Problem 15"
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+ | == Video Solution by OmegaLearn (Extending Lines, Angle Chasing, Trig Area) == | ||
+ | https://youtu.be/QtSbAKUb1VE | ||
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+ | ~ pi_is_3.14 | ||
==See Also== | ==See Also== | ||
{{AMC12 box|year=2021|ab=B|num-b=14|num-a=16}} | {{AMC12 box|year=2021|ab=B|num-b=14|num-a=16}} | ||
{{MAA Notice}} | {{MAA Notice}} |
Revision as of 21:25, 11 February 2021
Contents
Problem
The figure is constructed from line segments, each of which has length . The area of pentagon can be written is , where and are positive integers. What is
Solution
Let be the midpoint of . Noting that and are triangles because of the equilateral triangles, . Also, and so .
~Lcz
Video Solution by OmegaLearn (Extending Lines, Angle Chasing, Trig Area)
~ pi_is_3.14
See Also
2021 AMC 12B (Problems • Answer Key • Resources) | |
Preceded by Problem 14 |
Followed by Problem 16 |
1 • 2 • 3 • 4 • 5 • 6 • 7 • 8 • 9 • 10 • 11 • 12 • 13 • 14 • 15 • 16 • 17 • 18 • 19 • 20 • 21 • 22 • 23 • 24 • 25 | |
All AMC 12 Problems and Solutions |
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