# Day 21: This Diagram Looks Familiar

Geometry Level 2

A cyclic quadrilateral has its sides extended and they do meet, creating points $$E$$ and $$F$$ in the diagram.

As shown, $$E$$ and $$F$$ form a circle together with two vertices of the quadrilateral $$($$say $$B$$ and $$D).$$

Find the angle between line segments $$EF$$ and $$AC$$.

×