X,Y X, Y\,X,Y and Z Z\,Z are three points on the edge of a circular disc, centre WWW. XWZ XWZ\,XWZ is a diameter.

Show that angle XYZ XYZ\,XYZ is exactly 90∘90^\circ90∘.
You must not use any circle theorems in your proof.
Practise Eduqas GCSE Maths Proof of the Circle Theorems with exam-style questions for Foundation and Higher tier. 20 questions, matched to the Eduqas GCSE Maths (C300QS) specification and written in Component 1 and Component 2 style. Every question includes a full worked solution and mark scheme, so you can see where marks are awarded rather than just whether you got the answer right.