Question

question
figure 1 and figure 2 below are congruent. which side corresponds to side $su$?

Explanation:

Congruent figures have matching corresponding sides. By comparing the side lengths and the position of $\overline{SU}$ in Figure 1 (a short side connecting vertices S and U) to the sides in Figure 2, the corresponding short side is $\overline{BC}$, which connects vertices B and C and matches the length and relative position of $\overline{SU}$.

Answer:

$\overline{BC}$