Quadrilaterals, or a four sided shape, are fundamental shapes in geometry. They consist of (from most general to complex):
  1. Trapezoids - One pair of parallel sides.
  2. Parallelograms - Two pairs of parallel sides.
  3. Rectangles - A quadrilateral with four right angles.
  4. Kites - Two congruent adjacent sides.
  5. Rhombuses - All sides congruent.
  6. Squares - All sides equal and all angles 90o
From this diagram, it should be very easy to see how these figures are drawn.
Mascheroni Construction for the Square

Given points A and B:
  1. Draw a circle at A and B (blue). They intersect at C. Draw an identical circle at C (blue), that intersects circle B at D. Draw an identical circle at D (blue) that intersects circle B at E.
  2. Draw a circle at A so that it crosses D (purple). Draw a circle at E so it crosses C. These two circles cross each other at F.
  3. Draw a circle at B (cyan) so that it crosses F. This circle intersects circle A (blue) at G.
  4. Draw a circle at G (yellow) so that it crosses A. This circle intersects circle B (blue) at H. ABHG is square.

© 2003 Robin Hu