An equilateral triangle inside a rectangle. What is red : yellow : blue?
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Primary colours
Tag: rectangle
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The basketball court
An orange circle is squeezed inside a rectangle. Show that no matter how the blue point moves on the circle, the derived points Q and P will satisfy |QL| = |KP|.
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Falling pillar II
Three congruent rectangles on a line. Prove that the four red points are cyclic.
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The falling pillar
Three congruent rectangles on a line. What’s the angle α?
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Night mountain
A rectangle containing three line segments. What fraction is blue?
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Corner to corner
A rectangle inside a rectangle. What is the green area?
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The ball pit
Two rectangles contain 6 congruent circles. The common rectangle side passes through the top centre. What’s yellow : red?
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Shine your light
A quarter circle of radius 1, a rectangle touching the circle in an arbitrary point and a yellow quadrilateral. What is the minimal perimeter of this quadrilateral?
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The small cog
Two circles, a rectangle and two line segments. Prove that the red points are collinear.
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The personal letter
Two rectangles share two vertices. What’s the green fraction?