Find the perminter of 9.58m 11m 15m and 9m

Omar is going on a road trip! the car rental company offers him two types of cars. each car has a fixed price, but he also needs to consider the cost of fuel. the first car costs $90 to rent, and because of its fuel consumption rate, there's an additional cost of s0.50 per kilometer driven.

Acircle has a circumference of 28.36 units what is the diameter of the circle

Can someone me with these two circle theorem questions asap?