Question

for two right triangles to be congruent, which of the following must be true? their corresponding angles must be equal in measure and corresponding sides must be proportional. only their corresponding sides must be equal in measure. their corresponding sides and angles must be equal in measure. their corresponding angles must be proportional.

Explanation:

Congruent triangles have identical shape and size. This means all corresponding sides and all corresponding angles are equal in measure. For right - triangles, the same rule applies. Corresponding angles being equal and sides being proportional is for similar triangles. Just equal sides is not enough as angles also need to match, and angles cannot be proportional in the context of congruence.

Answer:

Their corresponding sides and angles must be equal in measure.