# Engineering Statics Question

1. Jun 29, 2015

### narutoish

1. The problem statement, all variables and given/known data

2. Relevant equations

F^2 (resultant ) = F1^2 + F2^2 -2F1F2cos(theta)

3. The attempt at a solution

i calculated the magnitude using the equation above and it ended up being :

F (resultant) = F sqrt(2-2cos(theta))

i dont know how to solve for the angle.

2. Jun 29, 2015

### Nathanael

Well in this particular case you can use symmetry (the magnitude of the forces are the same) to find it out.

In general, you could find the angle between two angles by solving for $\phi$ in this equation: $\vec a\cdot \vec b=|a||b|cos\phi$
(Of course, you would want to use some coordinate system to find $\vec a\cdot \vec b$)

3. Jun 30, 2015

### narutoish

So in this case we say it's theta/2?

4. Jun 30, 2015

Yep