*The ropes of a swing are 4 metres long, and the seat is 30 cm above the ground when it s t its lowest point. When Roberta uses the swing, the weat reaches a height of 2 metres above the ground on each side of the vertical. Calculate the angle APB through which she swings.*

The picture of the swinging looks kind of like an upside down ice cream cone. The ropes are attached at P (the pointy end of the cone) and she swings the rope from A to B. The rounded part-of-a-circle part at the bottom is her path, and is the arc I have to find the angle for.

I've drawn lines from A to B and from P down to the ground. I've labelled where the vertical line crosses AB as X and where it reaches the arc as Y. I know that XY has to be 2 - 0.3 = 1.7, so PX has to be 4 - 1.7 = 2.3. Also, they gave me that AP = BP = 4.

What next?