This last gentleman ascertained, by weighing, that the area of the circle is very nearly that of the square on the side of the inscribed equilateral triangle: which it is, as near as 3.162 ...
"A Budget of Paradoxes, Volume II (of II)"
Augustus de Morgan
I was delighted to find that my little tent was impervious to water, though its thickness was but of one layer of blanket: it was a single ridge with two poles, 7 feet high, 8 feet long, and 8 feet broad at the base, forming nearly an equilateral triangle in front.
"Himalayan Journals V2."
J. D. Hooker
Even in the first proposition of all, where he constructs an equilateral triangle on a given base, he uses two circles which are assumed to intersect.
"Mysticism and Logic and Other Essays"
Bertrand Russell