Given:
Consider the below figure attached with this question.
To find:
The measure of angle 3.
Solution:
According to intersecting secant theorem, if two secants of a circle intersect each other outside the circle, then the angle on the intersection is half of the difference of the intercepted arc.
![\text{Angle on intersection}=(1)/(2)(\text{Major arc}-\text{Minor arc})](https://img.qammunity.org/2022/formulas/mathematics/high-school/76w25joccamfjtvtnnc3jddbte1uc7vb9i.png)
Using the intersecting secant theorem, we get
![m\angle 3=(1)/(2)(m(arcXY)-m(arcWZ))](https://img.qammunity.org/2022/formulas/mathematics/high-school/3d6s7yv4b8p6nig012fy8wyliwwp69a73o.png)
![m\angle 3=(1)/(2)(85^\circ-25^\circ)](https://img.qammunity.org/2022/formulas/mathematics/high-school/g93fn6tb0t0xpuieot6eiivptxclfk3okz.png)
![m\angle 3=(1)/(2)(60^\circ)](https://img.qammunity.org/2022/formulas/mathematics/high-school/p7ldt0wc6plq8ecq5lbql1zr77gb5ol21u.png)
![m\angle 3=30^\circ](https://img.qammunity.org/2022/formulas/mathematics/high-school/ye4n0mq05c7t4ehikddnfl9j49vda00ecf.png)
Therefore, the measure of angle 3 is 30 degrees.