rectangle vs trapezium

rectangle

noun
  • Any quadrilateral having opposing sides parallel and four right angles. 

  • Such a quadrilateral that is oblong (longer than it is wide): one that is not regular (equilateral), that is, any except a square. 

trapezium

noun
  • A quadrilateral with two sides parallel and two sides non-parallel. 

  • The trapezium bone of the wrist. 

  • A region on the ventral side of the brain, either just back of the pons Varolii, or, as in man, covered by the posterior extension of its transverse fibers. 

  • A quadrilateral with two sides parallel. 

How often have the words rectangle and trapezium occurred in a corpus of books? (source: Google Ngram Viewer )