stuck on vector question (P3)
I'm stuck on this, I'm sure it's probably something very simple :/
In triangle OAB, the vector OA = 6a and the vector OB = 6b. The midpoint of OA is M and the point P lies on AB such that AP : PB = 2:1. The midpoint of OP is N.
I've done a) Calculate, in terms of a and b the vectors AB, OP and MN.
The part I'm stuck on is b) Show that the area of the quadrilateral AMNP is half the area of triangle OAB.
Any help/pointers would be much appreciated.
In triangle OAB, the vector OA = 6a and the vector OB = 6b. The midpoint of OA is M and the point P lies on AB such that AP : PB = 2:1. The midpoint of OP is N.
I've done a) Calculate, in terms of a and b the vectors AB, OP and MN.
The part I'm stuck on is b) Show that the area of the quadrilateral AMNP is half the area of triangle OAB.
Any help/pointers would be much appreciated.