Quadrilateral ABCD is both a rhombus and a rectangle.
I got 13.14 for f, since the scale factor is 1.75.
Yes, because every time you subtract 7
In the question, the angles proves that this triangle is an isoceles triangle.
So we can set the two sides equal:

Add

to both sides of the equation:

Divide both sides by 2:

We find that

. AC is also x, so, it is 6 too.