Definition of parallelogram in US English:



  • A four-sided plane rectilinear figure with opposite sides parallel.

    • ‘His vertical stripes have been put onto a slant, and whittled down to slender triangles or widened into parallelograms or pyramids.’
    • ‘Four congruent sides lie on two parallel lines, and pairs of these sides define parallelograms of equal area.’
    • ‘The building is in the form of a rectangular parallelogram, 294 feet five inches long by 219 feet nine inches wide, covering an area of 7,188 square yards.’
    • ‘Because the direction of the slope did not coincide with the axis of the view, the architect made the plan in the shape of a parallelogram.’
    • ‘In the deformation, the parallelograms always remain parallelograms, because their opposite sides remain equal, but the angles change.’


  • parallelogram of forces

    • A parallelogram illustrating the theorem that if two forces acting at a point are represented in magnitude and direction by two sides of a parallelogram meeting at that point, their resultant is represented by the diagonal drawn from that point.

      • ‘Parallelogram of Forces is the famous theorem that can be used to determine the resultant of two forces acting at a point.’
      • ‘This caused a deflection, which if it be analyzed, both directions taken together would be found to be a parallelogram of forces.’


Late 16th century: from French parallélogramme, via late Latin from Greek parallēlogrammon, from parallēlos ‘alongside another’ + grammē ‘line’.