You Do Need power plug adapter while traveling from Belgium to Bangladesh.

Here is Why You Need An Adapter

The outlet and plug type used in Bangladesh are A, C, D, G and K and in Belgium are C and E. This is how they look like.

Belgium

In Belgium, outlets of type C and E are in use.

Type C

Type E

Bangladesh

In Bangladesh, outlets of type A, C, D, G and K are in use.

Type A

Type C

Type D

Type G

Type K