How the resultant depends on the angle

Two forces of $3\ \text{N}$ and $4\ \text{N}$ act at a point. As the angle between them grows from $0^\circ$ to $180^\circ$, how does the size of their sum change? You will make the program work it out for every angle, and draw it.

The idea. For an angle $\theta$ between the forces,

Your tasks.

1. Find R for every angle in the list angles.
2. Find the largest and the smallest values of R.
3. Find the angle at which R is closest to $5\ \text{N}$.