Hello candidate,

Because of limitation and restriction on the number of answering methods available on the website it's not possible for me to reduce you the mathematical expression of the to cartesian lines and finding out their point of intersection from which we can find out the angle of contact.

But, here's the formula for it- tan theta = | (tan theta 1- tan theta 2)/ (1+ tan theta 1* tan theta 2)|

Good Luck!!