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#### Albert

##### Well-known member

- Jan 25, 2013

- 1,225

given PC=3, PA=4,PB=5 ,please find the side length of the equilateral triangle

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- Thread starter
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- Jan 25, 2013

- 1,225

given PC=3, PA=4,PB=5 ,please find the side length of the equilateral triangle

- Mar 10, 2012

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Rotate the trianlge by 60 degrees about the point C. Let $P'$ be the new position of $P$. Then $\angle P'PA=90$. Thus we get a triangle $CPA$ with $\angle CPA=150$ and $PC=3, PA=4$. To find $AC$.

given PC=3, PA=4,PB=5 ,please find the side length of the equilateral triangle

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- Jan 25, 2013

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- Mar 10, 2012

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Brilliant solution!