Area of a parallelogram, step by step

A parallelogram uses exactly the arithmetic its rectangle would: base times height.

The question
617 cm²

Area of a 6 by 17 parallelogram

6 cm 17
  1. A parallelogram. Two of its numbers matter and they are not the two longest lines — find them before working anything out.
  2. The base is the side it stands on: 6 cm.
  3. The height is the DASHED line — straight up from the base, at a right angle to it: 17 cm. It is not the sloping side, even though the sloping side is longer and is written right next to it.
  4. Slide the triangle off one end round to the other and it is a rectangle — same base, same height. So there is no halving here: 6 × 17 = 102 square cm.

How it works.

  1. 01

    A parallelogram. Two of its numbers matter and they are not the two longest lines — find them before working anything out.

  2. 02

    The base is the side it stands on: 6 cm.

  3. 03

    The height is the DASHED line — straight up from the base, at a right angle to it: 17 cm. It is not the sloping side, even though the sloping side is longer and is written right next to it.

  4. 04

    Slide the triangle off one end round to the other and it is a rectangle — same base, same height. So there is no halving here: 6 × 17 = 102 square cm.