Finding the Angle Between Two Vectors with Equal Magnitudes

[madinsane]

Homework Statement

Vectors A and B have equal magnitudes of 10.0. If the sum of A and B is the vector 3.13j , determine the angle between A and B

Homework Equations

none

The Attempt at a Solution

I gave both A and B the length r=10
I don't know how to add them together if I don't know them.
Please tell me where to start

 

[jedishrfu]

When you add two vectors you place the second on the tip of the first the addition is then the vector from the base of the first to the tip of the second. If you draw it out it's a triangle and since A and B have equal lengths then it's an isosolese? triangle.

 

[madinsane]

When you add two vectors you place the second on the tip of the first the addition is then the vector from the base of the first to the tip of the second. If you draw it out it's a triangle and since A and B have equal lengths then it's an isosolese? triangle.

okay, which would make the angle 45 degrees?