What must be the length of ZY in order for ZY to be tangent to circle X at point Y?

Hello! Remember you have to write complete questions in order to get good and exact answers. I'll assume that you have a circle X having two tangent lines that intersect at a point outside the circle. From geometry, we know that from any point outside a circle, two tangents to that circle are always congruent to each other if they meet at the mentioned point. So if the point of intersection is called Z, and a line is tangent to the circle at a point Y, ZY must be equal to ZW because ZW is tangent to the same circle at point W and meets ZY at a point outside the circle, then it is true that:

So the ZY must be equal 3 in order for ZY to be tangent to circle X at point Y