Questions tagged [quadrilateral]
For questions about general quadrilaterals (including parallelograms, trapezoids, rhombi) and their properties.
3 questions from the last 30 days
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How to construct the following isosceles trapezoid with compass and a straightedge?
Given:
$ABCD$ is an isosceles trapezoid with $BC \parallel AD$.
$MN$ is a segment such that $M\in AB$, $N\in CD$, $BC\parallel MN\parallel AD$.
$AM : MB = DN : NC = 1 : 2$.
$MN = AB = CD$.
$O$ is a ...
- 429
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How to prove that four points are concyclic under these given conditions?
I've stumbled upon the following problem that made me curious for quite a while. Below is one of many possible diagrams of the problem in question.
Given that $ABCD$ is a parallelogram with acute ...
- 429
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Non-concyclicity of the circumcenters of complementary triangles in a quadrilateral
About a year ago, I discovered a property related to quatrains, but I haven't been able to prove it. The property is rather strange, and I don't know where to begin proving it. If anyone can help me, ...
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