Is question a. Linear or non linear

What’s the answer ? use the picture to see the problem

Adolphin is swimming with her friend. the dolphin jumps to a height of 4.54.54, point, 5 meters above the surface of the water as her friend swims 9.89.89, point, 8 meters directly below her. what is the position of the dolphin's friend relative to the surface of the water? meters

Find the area of the region between a regular hexagon with sides of 6" and its inscribed circle.