Since it is given that ab ≅ ac, it must also be true that ab = ac. assume ∠b and ∠c are not congruent. then the measure of one angle is greater than the other. if m∠b > m∠c, then ac > ab because of the triangle parts relationship theorem. for the same reason, if m∠b < m∠c, then ac < ab. this is a contradiction to what is given. therefore, it can be concluded that

Step-by-step explanation:

We are given that

We have to prove that

Therefore, AB=AC

Suppose , angle B and angle C are not congruent.

Then, the measure of one angle is greater than the other.

If

Then ,

By using triangle parts theorem

It states that when an angle is greater than other then opposite side of greater angle is greater than the opposite side of other angle.

If

Then, AC < AB.

It is contradiction because we are given AB=AC.

Therefore, it can be concluded that

answer is the third choice:

3x^5+4x^4+x^3+2x^2-10x-7=0

step-by-step explanation: