What equation is not necessarily true?

Option B is not necessarily true.

Step-by-step explanation:

Option A.

AD =

Since triangle ABC is reflected to form triangle

So distance AD may be equal to distance . So this option is true.

Option B.

=

This statement is not correct because ≠

Option C.

m∠ACB = m∠

Since translated triangle and ΔABC are similar.

So the statement is true.

Option D.

m∠BAC = m∠

Since translated triangle and ΔABC are similar.

So the statement is true.

Therefore, option B is not necessarily true.