A level physics vectors

You can re-draw the diagram like this

Then you do pythagoras with the two numbers to get the resultant force

Then to get direction, you need to work out the angle that I've drawn on. I would do this by doing SOH/CAH/TOA with the triangle then doing 90 degrees - your answer.

Similar method for the next question

Hope that made sense

Pls could you explain b that’s the one I needed help on. I don’t know how to identify adjacent and opposite because there is no angle when you draw the third line .