I have no idea how to even start these problems. Please help.

If a 5 cm piece of wire is cut into two parts such that a square is formed by bending one part will have four times the area of a square formed by bending the other part, what is the length of the longer part?

A jet pilot plans to cover a 1000-km course at an average speed of 1000 km/h. For the first 800 km the speed is 800 km/h. At what rate must the remaining distance be covered?