Solve for the circumference * 11.8ft (radius)

Can somebody 1. what is the formula for finding the vertical distance between two points on a coordinate plane?

On traditional maps, earth is represented in a flat plane, or by euclidean geometry. however, a globe is a more accurate model that comes from elliptical geometry.how does a globe represent the fact that there are no parallel lines in elliptical geometry? the equator is not parallel to any other latitudinal lines. the north and south poles are never connected by a geodesic. the geodesics connecting the north and south poles never intersect. the geodesics connecting the north and south poles intersect at both of the poles.

At the beginning of the year, adrian's savings account balance was \$28$28. each week, he deposits another \$15$15 into that account, and he doesn't spend any of his savings. is his savings account balance proportional to the number of weeks since the start of the year?