an equilateral triangle, , is larger than that of any non-equilateral triangle. The ratio of the area to the square of the perimeter of an equilateral triangle, is larger than that for any other triangle. See also Brahmagupta quadrilateral, a cyclic quadrilateral with integer sides, integer diagonals, and integer area. Equiareal map Heronian triangle, a triangle with integer sides and integer area. List of triangle inequalities One-seventh area triangle, an inner triangle with one-seventh the area of the reference triangle. Routh's theorem, a generalization of the one-seventh area triangle. Orders of magnitude—A list of areas by size. Derivation of the formula of a pentagon Planimeter, an instrument for measuring small areas, e.g. on maps. Area of a convex quadrilateral Robbins pentagon, a cyclic pentagon whose side lengths and area are all rational numbers. References External links