Answer:
7.5
Explanation:
because OY is a radius like OX they will have equal length of 4 so OY = 4
Because of the circle theorem that says that tangents meet the the radius of a circle at 90 degrees, angle OYW is 90 degrees so the triangle OYW is a right angle triangle and we can use pythagoras theorem to get WY as:
![8.5^(2) - 4^(2) = WY^(2) \\\sqrt{WY^(2)}=WY=7.5](https://img.qammunity.org/2023/formulas/mathematics/high-school/y2xkrc04j33irlb200p166sax0rfta4hdy.png)