In the diagram is sector OAB with central angle 90° and radius 4. The sector is rolled in the direction of the arrow one complete rotation (without sliding) until it is once again oriented the same way on line l, as shown by image O'A'B'. Determine the length of the path that point O travels.
In diagram ① is trapezium ABCD with point P traveling around its perimeter. Point P begins at vertex Α, travels in a clockwise direction at 1 cm/sec passing vertices D and C, and finishes at vertex B. Diagram ② is a graph that shows the area of ΔABP as it varies over time. Determine how many seconds after the start the area of ΔABP is 48 cm² for the first time.