How far will a bicyclist riding at 20 miles per hour go in 2 hours?

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.

Hi my sisters and brothers can tell me the answer because i don’t understand the question

Express the following as a function of a single angle. cos(60) cos(-20) - sin(60) sin(-20)