Complete the connection between the two red pipes using any of the pipe shapes provided below, using as few pieces as possible.

This puzzle can be completed by placing just four extra pieces.

Pipe Shapes



  • You must have a continuous connection between each red pipe (A valid connection is achieved by aligning the ends of the pipes parallel to each other)
  • You must not make any adjustments to any of the pipes that have already been placed (the two red and two green pipes).
  • You must not place any pipes fully or partially outside of the grid.
  • You may make a connection with the green pipes already placed.
  • You may rotate any pipe you place, in increments of 90°.
  • You may place the same shape pipe more than once.
  • You are not required to use every pipe shape.

Valid solution example (six pieces).


1 Answer 1


Aha! The solution:

Side view

Top view
3D view: enter image description here

  • 1
    $\begingroup$ If only I could post a nice image instead... $\endgroup$ Nov 26, 2019 at 14:09
  • 2
    $\begingroup$ Oh! I get it now. Clever. Yes, It would be nice to have a good picture of it. $\endgroup$ Nov 26, 2019 at 14:13
  • 1
    $\begingroup$ @Jaap Such a nice 'aha' moment when you see it $\endgroup$ Nov 26, 2019 at 14:15
  • 4
    $\begingroup$ @JaapScherphuis Like this? (@DanielMathias Feel free to use this image in your answer) $\endgroup$
    – Ambo100
    Nov 26, 2019 at 14:46
  • 2
    $\begingroup$ I've edited @Ambo100's image into the answer because I was struggling to understand what you'd done. Hope you don't mind. $\endgroup$ Nov 26, 2019 at 17:49

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