Add vectors 
and 
each having magnitude of 100 unit and inclined to the X-axis at angles 45o, 135o and 315o respectively.
From the figure shown, it can be seen that vector 
and 
are in opposite directions. But they have same magnitude. Hence, both of them will add up to zero. The only remaining vector is 
. Hence, the magnitude of the resultant will be 100 units inclined at 45o to x- axis
2