Question
Thu July 19, 2012 By:
ABC is an equilateral triangle.Length of each side is 'a' and centroid is point O.Find
 
If |AB vector + BC vector + AC vector| =na then n=?
 

Vectors

Expert Reply
Thu July 19, 2012
Use parallelogram law of vector addition.
In a triangle,
vectors: AB + BC = AC.
Thus Vectors AB + BC + AC = AC + AC = 2AC
Taking modulous, |AC| = a
Thus n = 2.
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