(a)[2]
Find the value of $x$. Give a geometrical reason for your answer.
(b)[3]
Find the value of $y$. Give a geometrical reason for each stage of your working.
Mathematics 4024 · O Level · Circle theorems I
Circle theorems I — practice question
The points $B$, $D$, $E$ and $F$ all lie on one circle. $AC$ is a tangent to the circle at $B$. Angle $BEF = 50^{\circ}$ and $EF = BF$.