(a) If a triangle ABC with coordiantes A(2,7), B(2,9) and C(6,7) has a rotation and maps to triangle PQR with coordinates P(6,5), Q(8,5) and R(6,1), what is the centre of rotation? I want to ask in general, what's the way to find the answer? (b) An enlargement maps the triangle ABC with coordiantes A(2,7), B(2,9) and C(6,7) onto triangle XYZ with coordiantes X(12,12), Y(12,13) and Z(14,12). How to find the centre of enlargement? And this question, the enlargment scale factor is 1/2, right? (c) A shear maps triangle ABC with coordiantes A(2,7), B(2,9) and C(6,7) onto triangle LMN with coordinates L(2,10), M(2,12) and N(6,16). How to find the shear factor? And is this transformation first with a reflection and then a shear? (d) A triangle ABC wiht coordinates A(1,1), B(0,2) and C(3,1) is reflected in the line y=-x. How to find the matrix which represents the reflection? Please help me for these. I need to have examples of this to solve other problems.