The measure of angle XYZ in a circle, divided by lines UZ and WX, is found by subtracting the given angle UYW from 180. The correct expression is 1/2(110 - 42), corresponding to option a.
The sum of the angles in a triangle is always 180 degrees. In the given circle, angles XYZ and UYW form a linear pair, meaning they are supplementary (their sum is 180 degrees). Therefore:
![\[ \text{angle XYZ} = 180 - \text{angle UYW} \]](https://img.qammunity.org/2024/formulas/mathematics/high-school/54t466m1gsiq3zixtvco8tig8hox2jaltz.png)
Substitute the given values:
![\[ \text{angle XYZ} = 180 - 110 \]](https://img.qammunity.org/2024/formulas/mathematics/high-school/ecpfj3pz1ssfv0cnrwfwz0h6nk8jtjupyf.png)
![\[ \text{angle XYZ} = 70 \]](https://img.qammunity.org/2024/formulas/mathematics/high-school/7q2oyp06571j20xclrjm51hh8v1yuc7l1t.png)
So, the correct expression for the measure of angle XYZ is:
![\[ \text{1/2} * (110 - 42) \]](https://img.qammunity.org/2024/formulas/mathematics/high-school/72qpenuwjdalhwnd4w6e2275ybgz4yba86.png)
This corresponds to option a.
