Question

WILL MARK BRAINLIEST, JUST HELP ME PLS

Answer 1

Answer:

SAS theorem

Step-by-step explanation:

If $\frac{CE}{CB} = \frac{DC}{AC}$ and m∠ECD = m∠BCA, then the triangles are similar by the SAS theorem.

$\frac{EC}{BC} = \frac{14}{21} = \frac{2}{3}$           $\frac{DC}{AC} = \frac{18}{27} = \frac{2}{3}$

So,  $\frac{CE}{CB} = \frac{DC}{AC}$  and m∠ECD = m∠BCA because vertical angles are congruent

Therefore ΔECD is similar to ΔBCA by SAS theorem