Unfortunately you don't seem to have any questions here.

TheNakedScientists isn't a place to have your homework done for you.

You did mention a parallelogram in the title. When summing vectors, you can essentially redraw the vectors head to tail and the resultant vector is from the beginning of the first to the end of the last one. It doesn't make any difference which order you draw the vectors, and thus you get a parallelogram.

I am a bit rusty on my

Polar coordinate math.

One option might be to convert your problem into Cartesian coordinates by considering the vectors as right triangles with the axes, then using the old

SOH CAH TOA

Sin(θ) = opposite over hypotenuse

Cos(θ) = adjacent over hypotenuse

Tan(θ) = opposite over adjacent.

In Cartesian coordinates, you can simply add all of the X components, and add all the Y components of the vectors.