Determine the largest area of an isosceles triangle that is enclosed within a unit cube.
What is the answer if the triangle is equilateral?
Isosceles: For the base, use the diagonal of the cube's base. Put the
apex on an opposed corner. The height is the distance between
(1/2, 1/2, 0) and (0, 0, 1) = sqrt(3/2), Area = (1/2) sqrt(2) sqrt(3/2)
Area = sqrt(3)/2
Equilateral: Use 3 non-planer vertices of the cube. Each side is sqrt(2).
Again, Area = sqrt(3)/2