Three tangent semicircles and a circle. One tangency point is shown. Prove that red : green = yellow : blue.
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The maternal bond
Month: March 2023
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The cocktail
A triangle with two circles and two line segments. Prove that it is isosceles.
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Voting eccentric
A square with a circle and a tangent. The tangency point lies on the diagonal. What fraction is red?
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The bike chain
A square containing a semicircle, a circle and two tangents. What’s the angle α?
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The Czech flag
A square is divided in three parts. What fraction is red?
A triangle and two semicircles. What’s the angle α?
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Three’s a crowd
Four equilateral triangles. Prove that the red quadrilateral is a parallelogram.
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Hang a right
Two circles, one having its centre on the other, and four line segments. Prove that the three coloured line segments are congruent.
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North by Northwest
An equilateral triangle and a rectangle. What’s the angle α?
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Ice cube II
A square with an extended side. What’s the angle α?