# Questions tagged [geometry]

A puzzle related to shapes, geometric objects (polygons, circles, solids, etc.) of any number of dimensions, the relative position of figures, and the properties of space. Use with [mathematics]

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### What is the maximum number of fish possible in your tank?

You want to put some fish in a square tank. But these fish fight whenever they are in the same tank. Sadly, you have only 1 tank, but you can put glass panes inside the tank to divide it, not ...
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### 3³+4³+5³=6³ Puzzle

A classic puzzle asks us to break a 6x6x6 cube into the smallest number of pieces which can be reassembled into 3 physically separate cubes of sizes 3, 4, & 5. 3³+4³+5³ =27+64+125 =216 =6³ An 8-...
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### Make a Venn diagram with five triangles

A Venn diagram consists of a set of partially overlapping shapes on a plane, arranged in a particular way: for any particular labelling of each of the shapes as "inside" or "outside&...
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### Need some help with my math homework (pretty please?)

Can someone help with a problem from my math textbook? This is the problem I'm stuck on: I don't really get how these kinds of problems work. I think they want me to find the width of the rectangle? ...
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### Tile dominoes in a 3x10 space [closed]

How many ways are there to tile 1x2 (unmarked) dominoes in a 3x10 space? This is a harder version of Tile dominoes in a 2x10 space, since that was too easy.
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### Make exactly 101 squares using as few lines as possible

With how few straight lines can you make exactly 101 squares? The squares don’t necessarily have be the same size. Clarification 1: By lines, I mean you can use mathematical line segments and/or ...
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### ORIGAMI: Above and beyond

It's been a long time since I've posted an origami puzzle! An origami puzzle is solved with some thickness $x$ iff it can be folded into a rectangle (possibly a square) with thickness $x$ everywhere. ...
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### origami SNY t28

It's been a long time since I've posted an origami puzzle! Fold the shape into a rectangle such that the rectangle is 28 layers thick everywhere. The purple part is the puzzle. Although solutions are ...
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### Try Triling ("Triangular-Tiling")

You are given a grid. Some of the cells in the grid are labelled with positive numbers. You must partition the grid into triangles. There must be a triangle for each labelled cell Each cell must be ...
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A deadlock is a position in which neither player has won and neither player has a legal placement available. My question is, "Can you find a deadlock position in Minefield?" And, if you ...
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### Two digits in one

Here is a digit: However, it is, at the same time, another digit. How can it be?
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### origami J-SHAPED t2

It's been a long time since I've posted an origami puzzle! Fold the shape into a rectangle such that the rectangle is 2 layers thick everywhere. The red part is not included in the puzzle; the purple ...
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### Geometry Puzzle: Tangent Circles with Integer Radii

Take as a semi-related example a series of circles with radii 10, 9, 8, ..., 2, 1. Place the first (largest) circle in the center and subsequent circles around it, keeping tangency between subsequent ...
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### ORIGAMI PUZZLES completed version

You may have seen some posts by Sunny Lu here on my origami puzzles. Now, the full version is out! The goal is to fold the paper into a rectangle (or square) with constant thickness (see examples), ...
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### Tiling a 16x16 square with 1x4 rectangles

Consider a 16x16 square subdivided by grid lines into unit squares. It is easy to completely tile (no overlaps, no gaps) this square with 64 1x4 rectangles. Each 1x4 rectangle in the tiling (no ...
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### Can you tile a 15x16 rectangle using eight rectangles whose sizes are 1x2, 2x3, 3x4, ... 8x9?

Can you tile a 15x16 rectangle using eight rectangles whose sizes are 1x2, 2x3, 3x4, ... 8x9? No two rectangles can be the same size.
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### Ernie and the conduits of constant cross-section

It all started last week, when Acme Engineering loaned him a prototype version of their 3D Home Printer (this was as a reward for Ernie providing them, patent-free, with a suitable building material - ...
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