Difference between revisions of "1991 AHSME Problems/Problem 29"
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Revision as of 21:05, 20 April 2024
Problem
Equilateral triangle has on and on . The triangle is folded along so that vertex now rests at on side . If and then the length of the crease is
Solution
has side length . Let and . Thus, and . Applying Law of Cosines on triangles and using the angles gives and . Applying Law of Cosines once again on triangle using the angle gives so The correct answer is .
See also
1991 AHSME (Problems • Answer Key • Resources) | ||
Preceded by Problem 28 |
Followed by Problem 30 | |
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 • 26 • 27 • 28 • 29 • 30 | ||
All AHSME Problems and Solutions |
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