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Is it possible to divide an equilateral triangle into 5 equal (i.e., obtainable from each other by a rigid motion) parts?

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Does "reflection" count as rigid motion? – kennytm Oct 29 '10 at 17:20
I think it does not leave the arrangement of triangle angles unchanged so no. – Jaska Oct 29 '10 at 20:10
up vote 2 down vote accepted

You might want to look at:

and the references given there.

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In particular, look at the pinwheel tiling, which is for right triangles. See – lhf Oct 30 '10 at 2:18
Umm. I was looking a solution for equilateral triangle so how right triangle helps me? – Jaska Oct 30 '10 at 12:02
It seems that, according to Theorem 7 (on page 116) of the reference given by Joseph Malkevitch, the answer to your question is "no." – Joel Reyes Noche Nov 16 '11 at 3:59

The answer is "yes", it is possible to divide equilateral triangle into $5$ equal parts, see the picture picture below which comes from here:

enter image description here

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