In order for the Telerik javascript files to be loaded you will need to include the Telerik ScriptRegistrar at the end of your master page.
Checkout the following article: Telerik Extensions for ASP.NET MVC Manual
Looking specifically at the following section:
The ScriptRegistrar should be placed after all components on the page.
Typically you could put the ScriptRegistrar component at the end of
the master page.
The ScriptRegistrar searches for the Telerik javascript files in certain locations:
The ScriptRegistrar component looks for JavaScript files in the
following order:
First it will search for a folder with the same name
as the version of the Telerik.Web.Mvc.dll assembly located in the
Scripts folder of your ASP.NET MVC application. If such a folder is
found the ScriptRegistrar will look for the following extensions:
*.debug.js
*.min.js
*.js
If there is no such folder, the ScriptRegistrar will search in
the Scripts folder of the ASP.NET MVC application. It is better to
copy the folder with the version for easier upgrade.
Hope this helps.