Question

In the diagram B is the midpoint of a A and C. B is also the midpoint or E and F. C is the midpoint of A and D.

Find AD.

Answer 1

AD = 84

Explanation:

Since B is the midpoint of AC then AB = BC = 2x - 5

Since C is the midpoint of AD then AC = CD, thus

AB + BC = CD, that is

2x - 5 + 2x - 5 = x + 29

4x - 10 = x + 29 ( subtract x from both sides )

3x - 10 = 29 ( add 10 to both sides )

3x = 39 ( divide both sides by 3 )

x = 13

Hence

AD = AB + BC + CD

= 2x - 5 + 2x - 5 + x + 29 = 5x + 19, thus

AD = (5 × 13) + 19 = 65 + 19 = 84