Questions tagged [three-dimensional]

This tag is used for geometric puzzles, if one wants to stress that the setting is not 2-dimensional but 3-dimensional.

Filter by
Sorted by
Tagged with
109 votes
3 answers
8k views

The brain-curdling eldritch horrors and the third dimension

We're in the year 2016 so it's finally time to take puzzles to the 3rd dimension! So let's see what those beautiful times bring us today: (click to enlarge) Everyone of you clever sods could as ...
Avigrail's user avatar
  • 3,010
28 votes
4 answers
10k views

How do I arrange pencils so they all touch each other?

How do you arrange 6 pencils so that each one touches the other five? And what about 7 or 8?
Numberknot's user avatar
  • 3,012
15 votes
4 answers
740 views

Color the cubes, then assemble them to form a larger cube

Goal: Paint 27 cubes using three colors (for example, red, yellow, and blue), so that you can form a 3x3x3 cube with all surfaces in red (for example), a 3x3x3 cube all in yellow, and a 3x3x3 cube all ...
Daniel Mathias's user avatar
14 votes
2 answers
1k views

Puzzle about 6 infinite cylinders in space

You have 6 infinitely long cylinders (tubes) with the same radius R. Can you arrange them in space in a way that every cylinder touches the other 5? By touching, I mean have a common point or a line. ...
Евгений Павлов's user avatar
14 votes
7 answers
5k views

Fair n-sided dice

I have recently bought a fair $10$-sided dice for generating equally distributed random numbers from the range $1,2,\ldots,10$. Let me describe this dice in some more detail. Consider a regular 5-gon $...
Alexis's user avatar
  • 8,304
11 votes
2 answers
800 views

Chain Puzzle: Tabletop Games #7 - Maze

This is the seventh Chain Puzzle in the Tabletop Games series, in which all puzzles are themed around board games, card games, tile games, and the like. The answer to this puzzle is a thematic word or ...
Retudin's user avatar
  • 8,010
62 votes
2 answers
7k views

Can you perfectly wrap a cube with this blocky shape?

The following blocky shape: can be folded onto the surface of a cube in a way that perfectly covers the entire cube with no gaps and no overlaps. How can it be done?
plasticinsect's user avatar
37 votes
4 answers
2k views

Red Herring Bonkers In The Red Herring Bunkers

Please help me! Last weekend I hosted a hell of a party at my workplace (I'll invite you next time, promise). Of course, my boss didn't know about it. The next morning I entered the building and ...
Avigrail's user avatar
  • 3,010
30 votes
2 answers
1k views

A simple alien safe

Oh no!! Abducted by aliens and put into a labyrinth for ability testing - again! There is (obviously) no deeper meaning behind this all, but can you help me open this safe, as it undoubtedly contains ...
BmyGuest's user avatar
  • 18.1k
29 votes
1 answer
1k views

Every Fourth Wormhole

An entry in Fortnightly Topic Challenge #33: Surface Geometry Mazes
paramesis's user avatar
  • 4,599
28 votes
1 answer
932 views

How can this fractal shape perfectly cover a certain platonic solid?

The following fractal shape has a surprising property: This two-dimensional shape can be folded onto the surface of a regular polyhedron (one of the five platonic solids) in a way that perfectly ...
plasticinsect's user avatar
26 votes
1 answer
1k views

A firm farewell - Rest in piece

Avigrail's user avatar
  • 3,010
24 votes
1 answer
998 views

3D nonogram, beginner's edition

Trying out the concept of 3D nonograms. This one should be pretty simple. Name the depicted object.
Jafe's user avatar
  • 76.2k
19 votes
2 answers
2k views

Wooden Snake Puzzle

I have a wooden snake puzzle in my collection that has been unsolved for years. I wondered if any of you might be interested. I have fiddled with it, but think it might need dynamic programming or ...
Dr Xorile's user avatar
  • 22.8k
18 votes
1 answer
568 views

Wrapping a Galaxy Around a Cube

The following galaxy-like shape: can be folded onto the surface of a cube in a way that perfectly covers the entire cube with no gaps and no overlaps. How can it be done?
plasticinsect's user avatar
17 votes
2 answers
842 views

3D Masyu - A Die

Fold this net into a cube and solve this 3D Masyu. The original Masyu rules apply. In addition, question mark '?' should be replaced by either a black or white circle. Side note: Yeah, it's almost a ...
athin's user avatar
  • 34k
17 votes
1 answer
2k views

Introducing the 3D Connecting Wall!

This puzzle is part of the Monthly Topic Challenge #11: Now in 3D. A typical '2D' connecting wall puzzle (as made popular by the BBC quiz show, Only Connect) involves dividing a group of 16 seemingly ...
Stiv's user avatar
  • 134k
17 votes
1 answer
477 views

Cover a single cube with FIVE identical cube nets

Start with five identical cubes: Your challenge: Cut and unwrap all five cubes into five identical cube nets. Show how to re-fold these five cube nets to form the surface of a single larger cube, ...
plasticinsect's user avatar
15 votes
1 answer
670 views

3D nonogram – What's in the box?

This is a three-dimensional nonogram. The first six squares depict the layers of a $6\times6\times6$ cube. The final square gives the enumerations for the Z-axis, top to bottom. Some rules: The grid ...
Jafe's user avatar
  • 76.2k
14 votes
1 answer
2k views

Turn two cubes into one!

Here are two identical cubes: Your challenge: Start with two cubes of exactly the same size. Cut the surface of each of these two cubes along its edges and unfold the surface into a 2D shape. (So ...
plasticinsect's user avatar
13 votes
1 answer
412 views

Rhombicosidodecahedron Slitherlink

This is a Slitherlink puzzle, being played on the surface of a 3D object, a Rhombicosidodecahedron. If you are not familiar with Slitherlink puzzles, I don't suggest starting on this one. Rules in ...
Skosh's user avatar
  • 3,808
11 votes
1 answer
823 views

Three-dimensional light bulbs

This is a three-dimensional Akari puzzle (also known as Light Up). The six squares represent the layers of a $6\times6\times6$ cube, top to bottom. The objective is to add light bulbs into any number ...
Jafe's user avatar
  • 76.2k
11 votes
4 answers
618 views

Laser Beams in Helsinki Skies

(The first two chapters are just for flavour, you can safely skip to the TL;DR near the end.) This puzzle in situated Helsinki for a reason: for the city's "200 years as capital" celebration, the ...
Bass's user avatar
  • 76k
11 votes
1 answer
452 views

Multidimensional Travel

This is part 11 of the puzzle series Around the World in Many Days. Each part is solvable on its own. Deаr Puzzling, This is a three-dimensional crossword. The five squares in the picture represent ...
Jafe's user avatar
  • 76.2k
9 votes
1 answer
607 views

How many cubes are crossed by a diagonal?

A cuboid is composed by $81 \times 125 \times 128 $ cubes. How many cubes are crossed by a (main) diagonal of the cuboid? (note: I chose the numbers for the sides so that the case of the diagonal ...
mau's user avatar
  • 2,087
8 votes
1 answer
262 views

Nono-Cube: Approach at Your Own Risk

Inspired by jafe's 3D nonograms :) Answer is one word. This puzzle is a part of Ooohh, it all makes sense now! :D
Omega Krypton's user avatar
8 votes
2 answers
456 views

Nono-cube - Ultimate Puzzle Giant

Prologue - Instructions Shamelessly copied and pasted the following from @jafe's puzzle :P This is a three-dimensional nonogram. The first square gives the enumerations for the Z-axis, top to ...
Omega Krypton's user avatar
8 votes
1 answer
393 views

3D Statue Park: Daggers and dashes

This is a three-dimensional Statue Park puzzle.1 The five squares in the below image depict the five levels of a $5\times5\times5$ cube. The goal is to fit inside it the eight pieces shown in the ...
Jafe's user avatar
  • 76.2k
8 votes
2 answers
2k views

What puzzles can I make out of origami?

I recently made and solved a soma cube puzzle out of origami. What other puzzles can I make out of origami?                &...
abnry's user avatar
  • 315
8 votes
1 answer
445 views

3D tetromino placement

The following image depicts a $5\times5\times5$ cube. Insert any number of the pictured 3D-tetromino pieces into the cube to satisfy the conditions listed below. Pieces may be rotated in any direction....
Jafe's user avatar
  • 76.2k
7 votes
2 answers
319 views

A pyramid from a square

Given a square piece of paper. Cut it into 4 pieces that could be used to create a right angle pyramid - the 4 pieces are the faces of the pyramid.
Moti's user avatar
  • 2,229
6 votes
1 answer
1k views

Points on a cube

Professor Halfbrain has spent his entire weekend by placing colored dots on the surface of a huge wooden cube. His objective was to find large groups of dots that form the vertices of a regular ...
Gamow's user avatar
  • 45.4k
5 votes
1 answer
929 views

Find the object from its shadows

A 3D object is suspended in the air and it casts shadows on each orthogonal plane. The shadows are in the form of a circle, triangle and square, as shown in the diagram below. What is the shape of the ...
Dmitry Kamenetsky's user avatar
3 votes
1 answer
317 views

Seven octahedral nets to cover an octahedron

After solving Cover a single cube with FIVE identical cube nets I had the idea for this puzzle, which may be regarded as a natural generalisation to triangular grids. Find two different nets, A and B, ...
Parcly Taxel's user avatar
  • 6,996