Circle theorems II — practice question

Diagram (a): On the upper horizontal line, the points are A and C; on the lower horizontal line, the points are F, B and D; E is positioned beneath B. The angle at A is $26^{\circ}$. Triangle ABC is isosceles. AC is parallel to FBD. CBE is a straight line. The angle at B on the right-hand side is labelled $x^{\circ}$. Not drawn to scale. Diagram (b): A circle has diameter $PQ$, with P at the top and Q at the bottom. The tangent $SPT$ touches the circle at P. The angles shown inside are $17^{\circ}$ and $58^{\circ}$. The angle at the interior point is labelled $y^{\circ}$. Not drawn to scale.