User-1509636757 posted
It is a website application
If both are website application and you want to merge it and I will highly recommend to use either of the one and convert the other one.
However, you might want to look at this thread that describe similar solution for website application; in which single page compiled separately opposed to web application project in which only one language is possible:
Possible to combine C#.net, VB.net and ASP.net?
hope it helps./.