A, B, C and D lie on a circle. ADX and BCX are straight lines. $\angle BAD = x^\circ$ and $\angle DCX = y^\circ$.
(a)[2]
Explain why $x = y$. For every statement you write, include a geometrical justification.
(b)[2]
Show that triangles $ABX$ and $CDX$ are similar.
(c(i))[3]
Find the value of $BC$.
(c(ii))[1]
Complete the sentence.
The ratio area of triangle $ABX$ : area of triangle $CDX$ = .......... : 1.
Worked solution & mark scheme
This 8-mark question has a full step-by-step worked solution and mark scheme. One marking point: “Angles that lie on a straight line add up to $180^{\circ}$” …