Given:-
The traingle.
To find:-
The measure of angle theta.
So to find the angle value we use the formula,
![\cos \theta=(adjside)/(hypotnews)](https://img.qammunity.org/2023/formulas/mathematics/college/9kb8fweaqhs1av3j4ll69xjs77a37iz4sy.png)
So by using this value in the given data. we get,
![\begin{gathered} \cos \theta=(12)/(17) \\ \cos \theta=0.705 \end{gathered}](https://img.qammunity.org/2023/formulas/mathematics/college/418lt2yuymif5k4gkj7j7ezy93qnmwgrnt.png)
So as we need the value of theta to be found. we have,
![\theta=cos^(-1)(0.705)](https://img.qammunity.org/2023/formulas/mathematics/college/ntnq3d3rhinsb0wqzu5x11gnwrw7838bnd.png)
The value of theta will be the value of cos inverse of 0.75
So the value of theta is,
![\begin{gathered} \theta=\cos ^(-1)(0.75) \\ \theta=45.10^(\circ) \end{gathered}](https://img.qammunity.org/2023/formulas/mathematics/college/udy36kscin2vmabce9ctepqgjx7y3f3v64.png)
So the required value of theta is 45.10 degree.