You Do Need power plug adapter while traveling from Brazil to Denmark.

Here is Why You Need An Adapter

The outlet and plug type used in Denmark are C, E, F and K and in Brazil are C and N. This is how they look like.

Brazil

In Brazil, outlets of type C and N are in use.

Type C

Type N

Denmark

In Denmark, outlets of type C, E, F and K are in use.

Type C

Type E

Type F

Type K