Answer:
Option B
Step-by-step explanation:
Let us consider that these right triangles form a sort of proportion among one another. If that is so, we can list out which sides of one triangle correspond to which side of the other triangle;
[tex]BA and DE,\\AC and EC,\\BC and DC[/tex]
With this being said, it is given that BA = 84, and DE = 7. To prove that the could be proportional, let us form a like fraction;
[tex]DE / BA =\\84 / 7 = \\12\\\\Conclusion, BA = 12 * DE\\Conclusion, Sides Of Triangle DEC = 12 * Sides Of Triangle BAC[/tex]
With that, the length of AC in respect to EC can be represented as such;
[tex]AC = 12 * EC,\\156 - x = 12 * x,\\156 - x = 12x,\\156 = 13x,\\\\x = 12[/tex]
[tex]AC = 156 - x = 156 - 12 = 144[/tex]
Solution - Option B
