I'm lost, can someone explain?

if the arc length shown is 21.3 inches, find __ to the nearest hundredth of a radian.

Which statements about these triangles is true

Acar started driving from city a to city b, distance between which is 620 miles, at a rate of 60 mph. two hours later a truck left city b and started moving towards city a at a rate of 40 mph. how many hours after the truck's departure will the two meet?

2x minus y equals 6, x plus y equals negative 3