In triangle DEFDEFDEF, DE⃗=1i−2j+2k\vec{DE} = 1\mathbf{i} - 2\mathbf{j} + 2\mathbf{k}DE=1i−2j+2k, DF⃗=3i+4j−k\vec{DF} = 3\mathbf{i} + 4\mathbf{j} - \mathbf{k}DF=3i+4j−k
Find the vector EF⃗\vec{EF}EF
Find the length of the line DEDEDE
