Determine whether the triangles must be congruent. if so, name the postulate or theorem that justifies your answer. if not, explain. is 16 and 18 angle-side-angle or angle-angle-side? asap!

Problem 16)

We use ASA (angle side angle) to show the two triangles are congruent. Why ASA instead of AAS? Because the single pair of sides are between the two angles. 



Problem 18)

Similar to problem 16, we'll have two pairs of congruent angles, and a pair of congruent sides. However, the sides are NOT between the two angles. So that means we use AAS in this case.