What is the arc length of a circle that has a 9-centimeter radius and a central angle that is 2pi/7 radians

Translate the word phrase into a math expression. 15 fewer than the product of 4 and a number. (pls immediately)

The krasnapolski is a top-of-the-line hotel in amsterdam, the netherlands. among their many services, they rent bicycles to guests. the bicycle checkout is open 24 hours per day 7 days per week and has 50 bicycles on hand. on average, 10 guests request a bicycle each day, arriving completely randomly at all times of the day during the spring and summer seasons. guests keep bicycles for four days on average, with a standard deviation of two days. how long does a guest on average have to wait for a bike? a. approximately 24 hours b. approximately 0.033 hours c. approximately 4 days d. approximately 47 minutes

In the diagram, ab is tangent to c, ab = 4 inches, and ad = 2 inches. find the radius of the circle.