How is a parallelogram's area found?
Base times perpendicular height, just like a rectangle. The slant does not change the area, because sliding the top across does not add or remove space.
// maths › 2D Shapes
Parallelogram Area Calculator
Find the area and perimeter of a parallelogram from its base, perpendicular height and slanted side.
area = base×height ; perimeter = 2(base+side)
Frequently asked questions
Why not use the slanted side as the height?
Because the height must be the straight-up distance between the two bases, not the length of the tilted side. Using the side would overstate the area.
How do I get the perimeter?
Add up all four sides: twice the base plus twice the slanted side, or 2(base + side). Opposite sides are equal in a parallelogram.
Is a rectangle a parallelogram?
Yes. A rectangle is a parallelogram with right angles, so its height equals its side. Squares and rhombuses are parallelograms too.
Where does this come up?
Plots of land that lean, structural braces, and many tiling and design patterns built from slanted four-sided shapes.