You Do Need power plug adapter while traveling from Portugal 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 Portugal are C and F. This is how they look like.

Portugal

In Portugal, outlets of type C and F are in use.

Type C

Type F

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