Two regular pentagons share a vertex. What’s the angle α?
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Tipping point II
Tag: pentagon
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Ice cream cone II
Two regular pentagons sharing a vertex with extended sides and diagonals. Proof that the three red points are collinear.
A square and a regular pentagon share a vertex. What’s the angle α?
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Outside the pentagon II
A regular pentagon and two equilateral triangles. What’s the angle α?
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Staying in line
Three squares and a regular pentagon. Prove that the three red vertices are collinear.
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Pentagon pleasure
Two regular pentagons. The centre of the large one is a vertex of the small one. What is yellow : green?
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Pentagon divided
Given a pentagon ABCDE, construct the points T,R,Q,U such that the segments AT, AR, AQ, and AU divide the pentagon into five equal area pieces. (Using straight edge and compass. But you may divide a segment into a number of equal segments for free.)
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Pentagon offspring
Three regular pentagons are placed as shown. Prove that the three black line segments are concurrent.
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Playing fields
Show equality of the green and orange square playing field areas.
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Folding a pentagon
One side of a regular pentagon is folded back and forth as shown. Are the six red line segments congruent?