Final answer:
The length of side HJ in triangle HJK, which is congruent to triangle ABC, is equal to the length of the corresponding side AB in triangle ABC; therefore, HJ equals 3.5 cm.
Step-by-step explanation:
The student's question pertains to congruent triangles, specifically asking for the length of side HJ of triangle HJK which is congruent to triangle ABC.
The lengths of the sides of triangle ABC are given: AB = 3.5 cm, BC = 2.4 cm, and AC = 4.2 cm. To determine the length of side HJ, one must understand that congruent triangles have corresponding sides of equal length.
Hence the length of side HJ will be equal to the length of the corresponding side of triangle ABC.
Given that ΔABC ≅ ΔHJK, and since side AB corresponds to side HJ, we can conclude that:
HJ = 3.5 cm.