In triangle PQRPQRPQR, PQ⃗=3i−4j+2k\vec{PQ} = 3\mathbf{i} - 4\mathbf{j} + 2\mathbf{k}PQ=3i−4j+2k, PR⃗=7i+j−3k\vec{PR} = 7\mathbf{i} + \mathbf{j} - 3\mathbf{k}PR=7i+j−3k
Find the vector QR⃗\vec{QR}QR
Find the length of the line PQPQPQ