Finding Distance and Midpoint
Key Questions

#D=sqrt((P_(1_x)P_(2_x))^2+(P_(1_y)P_(2_y))^2+(P_(1_z)P_(2_z))^2)# Please see the following link for a full explanation and example:
What is the distance between#M(7,−1,5)# and the origin? 
We live in 3 dimensions.
We have East/West, North/South and Up/Down.
If something is 100 m East, and 120 m North and 80 m Above me, then the distance between us is a distance in 3 dimensions, And the middle of that distance is the midpoint.

The answer is
#M=((P_(1_x)+P_(2_x))/2, (P_(1_y)+P_(2_y))/2, (P_(1_z)+P_(2_z))/2)# .The midpoint is one of the easier things to calculate. Remember that mid is a synonym for average. To find the midpoint, we just average the components.