The points \(A(0, 2)\), \(B(-2, 8)\), \(C(20, 12)\) are the vertices of the triangle \(ABC\). The point \(D\) is the mid-point of \(AB\).
- Show that \(CD\) is perpendicular to \(AB\). [6]
- Find the exact value of \(\tan CAB\). [5]
- Write down the geometrical name for the triangle \(ABC\). [1]