Movement of rectangle overlapping triangle

As shown in a figure, there are rectangle ABCD and right triangle PQR. Rectangle ABCD moves at the speed of 1 cm/s to the right along the straight line XY from the position of a figure.

(1) Find the area of the portion with which the rectangle and the triangle have overlapped in 2 seconds.

(2) When it is in 3 seconds or more, the area of the portion with which the rectangle and the triangle have overlapped may become 2 cm². Find the time from the beginning of movement.

Answer