Find the radius of a circle with an area of 615.75 sq kilometers?

Ineed with this math problem p(65)=500×1.0325*65 the star means that you have to times it like 1.0325×1.0325?

A20? -foot ladder is placed against a vertical wall of a? building, with the bottom of the ladder standing on level ground 19 feet from the base of the building. how high up the wall does the ladder? reach?

The wheels of a bicycle have a diameter of 70cm. how many meters will the bicycle travel if each wheel makes 50 revolutions