import { NgModule } from '@angular/core' ; import { RouterModule , Routes } from '@angular/router' ; import { AboutComponent } from './about/about.component' ; import { GroundFailureComponent } from './ground-failure/ground-failure.component' ; import { SummaryComponent } from './summary/summary.component' ; const groundFailureRoutes = [ { children : [ { component : SummaryComponent , path : 'summary' } , { component : AboutComponent , path : 'about' } , { path : '' , pathMatch : 'full' , redirectTo : 'summary' } ] , component : GroundFailureComponent , path : '' } ] ; @ NgModule ( { exports : [ RouterModule ] , imports : [ RouterModule . forChild ( groundFailureRoutes ) ] } ) export class GroundFailureRoutingModule { }