Thursday 21 January 2016

geometry - Five graded difficulty isosceles right triangle into square tilings


Similar to: Unlucky tiling: Arrange thirteen right isosceles triangles into a square


Two difficult "Seventeen right isosceles triangles into a square" tilings


V.hard problem, 20 right isosceles triangles into a square


Each tiling has only one solution, the smaller lists will be easier but all should be possible by hand, computers allowed.


The five challenges are to arrange $7, 13, 14, 15, 16$ right isosceles triangles of the listed areas into a square of area $882$ with no gaps or overlaps. The square has a diagonal of length $42$.


$7:$ $9, 18, 36, 72, 144, 162, 441$



$13:$ $16, 18, 25, 32, 36, 50, 64, 72, 81, 98, 100, 128, 162$


$14:$ $1, 2, 4, 8, 9, 16, 18, 25, 32, 36, 64, 98, 128, 441$


$15:$ $1, 2, 4, 8, 16, 25, 32, 36, 50, 64, 72, 98, 121, 128, 225$


$16:$ $1, 2, 4, 8, 16, 18, 25, 32, 49, 50, 64, 81, 98, 128, 144, 162$


The answer tick will be given to whomever posts the greatest number of "placed triangles" in completed puzzles first. In the unlikely event of a tie, the solver that got the highest scoring single puzzle wins.


By way of illustration/clarification, here are the right isosceles triangles of area


$1, 2, 4, 9, 16, 18, 50$


arranged into a $10\times 10$ square:


10x10_7



Answer




Here are the solutions to the five problems.



enter image description here
I was able to find by hand the first three solutions. The first one, in particular, can be downsized by a factor of 3 in all dimensions to simplify work. The last two I used PolySolver to help. The general methodology is to stack several triangles, often doubling in area, together.



No comments:

Post a Comment

Understanding Stagnation point in pitot fluid

What is stagnation point in fluid mechanics. At the open end of the pitot tube the velocity of the fluid becomes zero.But that should result...