I need help pls ASAP show your work

For the equations below which statement is true ?

What is the circumference of a circle with an area of 50.24 cm²?

An incoming airplane is x miles due north from the control tower at an airport. a second incoming airplane is y miles due east of the same control tower. the shortest distance between the two airplanes is z miles. which of the following functions would best model the situation above?