Step-by-step explanation:

Answer:
SAS theorem
Step-by-step explanation:
If
and m∠ECD = m∠BCA, then the triangles are similar by the SAS theorem.

So,
and m∠ECD = m∠BCA because vertical angles are congruent
Therefore ΔECD is similar to ΔBCA by SAS theorem
Answer:
-18/3
Step-by-step explanation:
Multiply the denominator and numerator by the same whole number.
A, B, and C. all of them are reasonable choices and wouldn’t give any conclusion, because not everyone has the flu