Answer number 13 for me ill reward u handsomely with alot of points

The tiles below are pieces of a normal ecg tracing representing a little less than two heartbeats at a resting rate of 80 bpm. arrange the tiles in their correct order. rank from first to last. do not overlap any tiles.

Which angle is the smallest? also give me an explanation so i can complete it to other questions as well, : )

If the equation of a perpendicular bisector of a triangle is y = 2x + 7, what is the slope of the side that it is bisecting? explain how you know.