The relation isn't a function because a function is a relation where each x-value has only one corresponding y-value. Try to put a vertical line through that shape made by the graph to test if it's a function. If it passes through multiple points, it's not a function. For example, if you put the vertical line x=3 in that same graph, it will intersect with the relation at points (3, -3) and (3, 4), and therefore is not a function.
first you have to find the radius before you find the area. so given the height, the radius is 11.3 meters. then, you need to find the area behind the arc, which is 85.4 meters/
