If are unit vectors, find the angle between
Since,
Let &
Angle between is and angle between is
By vector addition method;
we have:
=2(1+cos θ)
=2(1-cos θ)
So,
Now in the parallelogram:
Area of parallelogram= (product of two sides and the sine of angle between them)
i.e. (1)
Also area of parallelogram= sum of area of all four triangle
And area of each triangle =
So, Area = 2
Since are supplementary
A= 4= (2)
From (1) &(2) we get: