How to rotate a UI element around a pivot by also adjusting its position?

Hello. I’m making a radial meter UI and I need to set a needle’s rotation like so:

How would I accomplish this? My brief research brought nothing of use up, all I could find was the Transform method RotateAround (Rotate nowadays) and some trigonometry trickery, however none of it was useful. I’m at a loss for what to do.