Could you help me solve the part(b)?

Problem 2. Recall that for any subspace V of R", the orthogonal projection onto V is the map projy : R" -> R" given by projy(I) = ill for all I E R", where i'll is the unique element in V such that I - I E V!. For any vector space W, a linear transformation T : W -> W is called a projection if To T = T. In each of (a) - (d) below, determine whether the given statement regarding projections is true or false, and provide a proof or a counterexample accordingly. (a) For every subspace V of R", the orthogonal projection projy : R" - R" is a projection. (b) For every projection 7 : R" -> R" and basis B of R", the B-matrix [T]s of T is a projection matrix, meaning that ([T]B)? = [Tls