Question

A, B, C, D are points on a line, with D the midpoint of segment BC. The

lengths of segment AB is 10; segment AC is 2; and segment BC is 12. What
is the length of segment AD?

Answer 1

Also BC = 12

B......6......D......6......C

Now, AC = 2.

A can be either left of C or right of C

If A is left of C , AB = 12-2 = 10 (Correct)

If A is right of C AB = 12 +2 = 14 (Incorrect)

So the points placing is as below

B......6......D....4....A..2..C

Length of segment AD = 4