Question

You and your friend are standing back-to-back. Your friend runs 20 feet forward and then 15 feet right. At the same time, you run 12 feet forward and then 9 feet right. You stop and throw a baseball to your friend, who catches it. How far did you throw the baseball?

Answer 1

40 ft

Explanation:

the starting point is like the origin on the coordinate grid.

let's say forward for your friends is the positive y direction, and right for your friend is positive x direction.

the end point coordinates of your friend are then

(15, 20)

forward for you (facing in the other direction) is the the negative y direction. and going right for you is then actually going in the negative x direction.

your end point is therefore

(-9, -12)

the distance between both points is then per Pythagoras (and the derived distance formula) :

distance² = (x1 - x2)² + (y1 - y2)² =

= (15 - -9)² + (20 - -12)² = 24² + 32² =

= 576 + 1024 = 1600

distance = 40 ft