13. Let T: Rd Rd be a linear transformation such that (Tu, Tv) = (u, v) for all u, v E Rd. Prove that, for any Jordan region A c Rd, the set T(A) is a Jordan region and |T(A)| = |A| 14. Let V1, ...,Vd be vectors in Rd and define 13. Let T: Rd Rd be a linear transformation such that (Tu, Tv) = (u, v) for all u, v E Rd. Prove that, for any Jordan region A c Rd, the set T(A) is a Jordan region and |T(A)| = |A| 14. Let V1, ...,Vd be vectors in Rd and define