UKMT Special (Problem 2121)

The diagram shows a circle and a trapezium ABCDABCD in which ADAD is parallel to BCBC and AB=DCAB = DC.

All four sides of ABCDABCD are tangents of the circle.

The circle has radius 44 and the area of ABCDABCD is 7272.

What is the length of ABAB?

[UKMT Hamilton Olympiad 20182018, H44]

Note by Yajat Shamji
8 months, 2 weeks ago

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1 vote

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Key point to realize is that the tangents to a circle from the same point will be of equal length.

Ethan Mandelez - 8 months, 1 week ago

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Correct method and solution!

Yajat Shamji - 8 months, 1 week ago

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You have until next Saturday, 3:003:00pm!

Yajat Shamji - 8 months, 2 weeks ago

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