A regular octagon with two diagonals and a square. Prove that the four red points are concyclic.

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geometry puzzles

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- Post author By Rik D. Tangerman
- Post date February 9, 2024
- No Comments on The ceiling lamp

A regular octagon with two diagonals and a square. Prove that the four red points are concyclic.

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- Post author By Marshall W. Buck
- Post date November 14, 2023
- No Comments on Wild floor tile

What is the ratio of areas, purple/green, when the orange octagon is regular (all angles equal)?

- Tags area, octagon, proportion, square

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- Post author By Marshall W. Buck
- Post date October 24, 2023
- No Comments on Three octagons

The rectangles are 3 by 4. Which of the three bounding octagons have similar shape?

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- Post author By Rik D. Tangerman
- Post date December 16, 2022
- No Comments on The purple square

A regular octagon of side length 2 with two diagonals and a square. What is the purple area?

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- Post author By Rik D. Tangerman
- Post date November 8, 2022
- No Comments on Eight corners

A regular octagon with two diagonals and two squares. What’s the area proportion of the blue to the red square?

- Tags area, octagon, proportion, square

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- Post author By Rik D. Tangerman
- Post date November 29, 2021
- No Comments on The chocolate muffin

Four isosceles triangles of base 1 and four of base √2 share their top vertex. What is the proportion brown : gold?

- Tags area, octagon, proportion, triangle

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- Post author By Rik D. Tangerman
- Post date September 6, 2021
- No Comments on The blue pill

A regular octagon containing a blue hexagon. All line segments have equal length. What fraction is blue?

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- Post author By Rik D. Tangerman
- Post date November 30, 2020
- No Comments on The circus tent

A regular octagon is coloured as shown. What fraction of its area is red?