Four points on the plane are vertices of three different quadrilaterals. How can this happen?
The problem is taken from "Kiselev's Geometry - Book I : Planimetry"
At first, I thought it could be like this :
But, the way diagonals are defined in the book:
Makes me think that the 3 figures I drew, are the same quadrilateral.
How do you think four points on the plane can be vertices of three different quadrilaterals