The Problem: In the diagram, the circles with centres P, Q, and R hav radii of 3, 2, and 1 respectively. Each circle touches the other two as shown. Find the area of triangle PQR.
I used the law of cosines to find angle P.
I then thought of using the sine or cosine formula to find the height (I thought of drawing a height from the centre R to where the circles containing P and Q touch). But I don't know that it's a right-angle triangle. I am stuck at this point.