Upper left (n = 5):


*****
****
***
**
*

Lower left (n = 5):


*
**
***
****
*****

More difficult ones:
Hint: you need to print out spaces using System.out.print(" ");
Upper right (n = 5):


*****
 ****
  ***
   **
    *

Lower right (n = 5):


    *
   **
  ***
 ****
*****

This is an example from CSci 1211 course.