There are multiple ways:
ng --version
The command above will result in the following output:
Angular CLI: 7.0.3
Node: 9.4.0
OS: darwin x64
Angular: 7.0.1
... animations, common, compiler, compiler-cli, core, forms
... http, language-service, platform-browser
... platform-browser-dynamic, router
Package Version
@angular-devkit/architect 0.10.3
@angular-devkit/build-angular 0.10.3
@angular-devkit/build-optimizer 0.10.3
@angular-devkit/build-webpack 0.10.3
@angular-devkit/core 7.0.3
@angular-devkit/schematics 7.0.3
@angular/cli 7.0.3
@ngtools/webpack 7.0.3
@schematics/angular 7.0.3
@schematics/update 0.10.3
rxjs 6.3.3
typescript 3.1.4
webpack 4.19.1
So, the version of Angular, Angular CLI, Node and many other packages can be verified from here.