jmc

Question

A map of the town that Annie, Barbara, and Charlie live in can be represented by the Cartesian plane. Annie is located at (6,-20) and Barbara is located at (1, 14). They agree to meet at the closest point that is equidistant from their current locations and walk upwards together to get to Charlie's location at (72, 2). How many units upward do Annie and Barbara walk together to get to Charlie?

Accepted Answer

Annie and Barbara will be meeting up at the midpoint of (6,-20) and (1, 14). We only need to find the y-coordinate of the midpoint since the problem says they only walk upwards from the midpoint to get to Charlie's location. (If you want, you can verify that the x-coordinate of the midpoint equals 7/2.) The y-coordinate of the midpoint is -20+142=-3. To get to Charlie at y=2, the girls walk 2-(-3)=5 units upward.