At 20 kilometers from shore the incoming boulders were located at 2800 meters of altitude. At 40 kilometers from shore, they were spotted at 4200 meters of altitude. And at 70 kilometers out, the boulders were passing at 5550 meters of altitude.
Are their shots too short or too long to hit us and by how much?

Question

anonymous · Answer

$$y = ax ^{2} + bx +c$$ where x is a horizontal distance and y is vertical. If you are given three points, put the coordinates of those in for x and y to get three equations to solve for a, b, and c.

anonymous · Answer

William how do you know how far we are

anonymous · Answer

Ok, I know that there will be three equations to solve for, but just not quite sure how to set them up.