# Coordinate Geometry-11

### From Homeworkwiki

**Find the area of the triangle having for its vertices the points (0, 0), (0, c), (h, k).**

**Solution:** Let O, A and B be the points (0, 0), (h, k) and (0, c).

Join OA, AB. Draw AD perpendicular to OB.

In Triangle OAB, if OB is considered as the base and AD as the height

Area of the Triangle OAB = 1/2 x OB x AD = 1/2 x c x h =1/2 ch