Does isosceles subsume equilateral?
March 3, 2005 11:11 AM Subscribe
Are equilateral triangles also isosceles?
posted by i_am_joe's_spleen to science & nature (25 answers total)
My daughter was given homework in which she had to identify isosceles triangles. We decided that given the definition "has two equal sides", an equilateral triangle must also be isosceles. Her maths teacher disagrees. It's been a long time since I did plane geometry, but I'm sure that the formal definition was not "two sides only"
I can't find authoritative, unambiguous references on Google. I'd love an online reference, but a dead-trees one would be good too.
I'm not going to buy a fight over geometry with a hapless primary school teacher but this is driving me nuts.