Answer:
Question 21: C.
Question 22: I.
Question 23: E.
Question 24: B.
Explanation:
#21: The first statement is presented in the "Given" section.
#22: Since the reflexive property states that anything is equal to itself, BC ≅ BC.
#23: C being the midpoint of AD means that C is the same distance from both point A and point D. This then means that AC ≅ CD.
#24: AB ≅ DB due to the given, BC ≅ BC (since it's the same side), and we've proven that AC ≅ CD using a midpoint. We've proven all three sides on the two triangles to each other are congruent. This means that we've proven the triangles using SSS, which is B.