Reckoning / Shape / Parallelogram
Plane figure · Quadrilaterals
Parallelogram
Two pairs of parallel sides. The height is measured at right angles to the base, not along the slanted side.
Dimensions
Results
area A
perimeter P
height h
Formulas
Cut the triangle off one end and move it to the other: the parallelogram becomes a rectangle b by h with the same area. Sliding the top along (a shear) never changes the area.
Checked: the A formula agrees with a Monte Carlo measurement of the shape itself, made from its geometric definition, every time the site is built.
Topology lens
Topologically a disc, like every figure here without a hole: Euler characteristic 1. Stretching turns it into a circle, a square or a star. More on the lens.