Question

triangle abc is congruent to triangle def. which statement must be true about the triangles? m∠a = m∠d; bc = de; m∠b = m∠f; ac = ef

Explanation:

When two triangles are congruent, corresponding angles are equal and corresponding sides are equal. In \(\triangle ABC\cong\triangle DEF\), \(\angle A\) corresponds to \(\angle D\), \(\angle B\) corresponds to \(\angle E\), \(\angle C\) corresponds to \(\angle F\), \(AB\) corresponds to \(DE\), \(BC\) corresponds to \(EF\), and \(AC\) corresponds to \(DF\). So \(m\angle A = m\angle D\) is the correct property for corresponding angles of congruent triangles.

Answer:

A. \(m\angle A=m\angle D\)