Answer:
Step-by-step explanation:
The problem with this kind o f question is that I likely can prove it, but I may not use the vocabulary that you do.
1 AC = BD Given
2 AC = AB + BC The sum of any two segments of a given line with is equal to another given line are equal. Put another way the sum of 2 parts of an equal line = the sum of any 2 parts of another equal line are equal. The sums are what is equal.
2a BD = BC + CD Same reason as above.
3 AB + BC = BC + CD The Since AC = BD then The sums on the the right making up AC and BD are equal.
4 AB = CD What I used to call the reflexive property. It means a segment appearing on both sides of an equal side can be subtracted out. A line segment is always equal to itself and can be subtracted out without loss of equality.
