Angular Routing for Single Page Application (ASP.Net MVC Web API)

1. User is presented with a list of companies
2. User selects a company, and is presented with a list of reports defined for that company

I have configured my angular appp as such:

angular.module('xcmApp', ['ngRoute', 'ngResource'])
.config(function ($routeProvider) {
    $routeProvider
    .when('/',
    {
        controller: 'companiesController',
        templateUrl: '/views/companylist.html'
    })
    .when('/Reports/:companyid',
    {
        controller: 'reportsController',
        templateUrl: 'views/reportlist.html'
    })
    .otherwise({ redirectTo: '/' })
})
.factory('companiesFactory', ['$resource',
    function ($resource) {
        return $resource('/api/companies', {}, {
            query: { method: 'GET', params: {}, isArray: true }
        });
    }
])
.controller('companiesController', function ($scope, companiesFactory) {
    $scope.Companies = companiesFactory.query();
})
.factory('reportsFactory', ['$resource',
    function ($resource) {
        return $resource('/api/reports/:companyid', {}, {
            query: { method: 'GET', params: { companyid: '@@companyid' }, isArray: true }
        });
    }
])
.controller('reportsController', function ($scope, reportsFactory) {
    $scope.Reports = reportsFactory.query();
});

My WebAPI Controller is simple:

[Route("api/[controller]")]
public class ReportsController : Controller
{
    // GET: api/values
    [HttpGet("{companyid}")]
    public IEnumerable<PBMMMIS.Data.WebReport> Get(string companyid)
    {
        return Xerox.XCM.PBMMMIS.Data.CompanyAPIDataContext.GetReports(companyid);
    }

}

I am not sure how to construct the routes to accept the companyid parameter, so that the report list can be fetched accordingly. Any help is sincerely appreciated.