Final answer:
Additional information or a diagram is needed to calculate the length of side pr and the measure of angle j.
Step-by-step explanation:
To determine the length of side pr in Δpqr and the measure of ∞j in Δjkl, we need more information or a specific diagram showing the triangles. Without additional details, it is not possible to calculate the length of side pr or the measure of ∞j.