A regular pentagon with a diagonal and a right triangle. What’s the angle α?
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It’s all right
Month: December 2022
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Uneven cups
Two semicircles and several line segments. Prove that the red line segments are parallel.
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The glass splinter
A triangle of which two sides and one angle are given. What’s the angle α?
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The triskelion
A circle containing an equilateral triangle and three squares. What fraction is purple?
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The Christmas star
Two congruent concentric equilateral triangles. Prove that the gold fraction is red/blue.
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The seesaw
A regular hexagon with three diagonals and two line segments at right angles. What is the proportion green : yellow : blue : orange?
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The consonant squares
Four squares and a rectangle. What’s the angle α?
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The Zamani suggestion
Two regular hexagons share a vertex. What’s the area proportion red : yellow hexagon?
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The forward lean
A square with a diagonal and an isosceles triangle. What fraction is brown?
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The purple square
A regular octagon of side length 2 with two diagonals and a square. What is the purple area?