1. angle DMA = angle BMC : vertical angles theorem
2. MD is congruent to MB : given
3. angle MDA is congruent to angle MBC ( alternate interior angles)
4. Triangle MDA is congruent to triangle MBC : by ASA postulate of congruency. ( option A)
What are congruent triangles?
Congruent triangles have corresponding angles and sides equal in measure. They are identical when superimposed, maintaining the same shape and size.
1. angle DMA = angle BMC : vertical angles theorem
2. MD is congruent to MB : given
3. angle MDA is congruent to angle MBC ( alternate interior angles)
4. Triangle MDA is congruent to triangle MBC : by ASA postulate of congruency.