The areas of two opposite quadrilaterals
The areas of two opposite quadrilaterals
The applet illustrate the property according to which thesum of the opposite quadrilaterals always equals half the area of the
quadrilateral ABCD, we construct a GeoGebra applet in which one can drag each
of the vertices of the quadrilateral ABCD, and for each location of the
vertices (including a concave quadrilateral), the screen shows the sum of the
areas of the opposite quadrilaterals.