Hello @ajeet_singh 
As far as I can tell, Cesium does not have a version requirement on which Angular you are going to use. For example, in this demo we have combined Angular 8 with Cesium 1.51.0
Please notice that there is a newer demo of the preceding code at GitHub - Developer-Plexscape/cesium-angular-example: An example application using Cesium with Angular. if you want to have a look.