Question

Determine the resultant of two vectors each of magnitudes 10m if the angle between them is 120 degree

Answer 1

As both vectors have the same magnitudes, the resultant vector will break the angle between them half-and-half. So, the angle between the side vectors and the resultant vector is 120/2 = 60 degree. Obviously, the obtained triangles built on the resultant vector and the side vectors will be equilateral (as an isosceles triangle with an angle 60 degree at the base) and the resultant takes magnitude 10 m.