Parallel bases and intersecting diagonals

Optional extension

In the diagram, \(AB\parallel CD\), \(AB=15\) cm, \(CD=5\) cm, \(CX=3\) cm and \(DX=4\) cm.

1. Complete this mathematical statement. \(\triangle ABX\) is ... to \(\triangle CDX\).[2]
2. Find the perimeter of \(\triangle ABX\).[2]
3. If the area of \(\triangle ABX\) is \(y\text{ cm}^2\), express the area of \(\triangle CDX\) in terms of \(y\).[2]