Here is your answer
[tex]<b>n= 32 </b>[/tex]
REASON:
[tex]<font color="blue" size=5>Concept used</font>[/tex]: Sum of interior angles of a polygon=
(2n-4)×90 degrees , where n is no. of sides
So,
[tex] (2n-4)×90= 5400 [/tex]
[tex] 2n-4= 5400/90 [/tex]
[tex] 2n-4= 60 [/tex]
[tex] 2n= 60+4 [/tex]
[tex] 2n= 64 [/tex]
[tex] n= 64/2 [/tex]
[tex] n= 32 [/tex]
HOPE IT IS USEFUL