It is given that ∠b ≅ ∠c. assume ab and ac are not congruent. if ab > ac, then m∠c > m∠b by if ac > ab, then m∠b > m∠c for the same reason. however, using the given statement and the definition of congruency, we know that m∠b = m∠c. therefore, ab = ac and ab ≅ ac.

It is given that ∠B ≅ ∠C. Assume AB and AC are not congruent. If AB > AC, then m∠C > m∠B by the triangle parts relationship theorem. If AC > AB, then m∠B > m∠C for the same reason.

However, using the given statement and the definition of congruency, we know that m∠B = m∠C.

Therefore, AB = AC and AB ≅ AC.

The answer is 10. sorry i was wrong the 1st time