MathDB
Triangle in the Cartesian Plane

Source:

June 8, 2009
analytic geometrygeometry

Problem Statement

The vertices of triangle PQR PQR have coordinates as follows: P(0,a),Q(b,0),R(c,d), P(0,a),\,Q(b,0),\,R(c,d), where a,b,c a,\,b,\,c and d d are positive. The origin and point R R lie on opposite sides of PQ PQ. The area of triangle PQR PQR may be found from the expression: (A)\ \frac{ab \plus{} ac \plus{} bc \plus{} cd}{2} \qquad (B)\ \frac{ac \plus{} bd \minus{} ab}{2}\qquad (C)\ \frac{ab \minus{} ac \minus{} bd}{2}\qquad (D)\ \frac{ac \plus{} bd \plus{} ab}{2}\qquad (E)\ \frac{ac \plus{} bd \minus{} ab \minus{} cd}{2}