Given:
Quadrilateral PQRS
P(o, o), Q(a+c, o), R(2a+c, b), S(a, b)
Find:
whether the diagonals are perpendicular using coordinate geometry
Solution:
If the diagonals are perpendicular, their slopes multiply to give -1.
The slope of PR is
(b-o)/(2a+c-o)
The slope of QS is
(b-o)/(a-(a+c)) = (b-o)/(-c)
The product of these slopes is
(b-o)·(b-o)/((2a+c-o)(-c))
This value will not be -1 except for very specific values of a, b, c, and o.
It cannot be concluded that the diagonals of PQRS are perpendicular based on the given coordinates.
