You Do Need power plug adapter while traveling from Madagascar to Ethiopia.

Here is Why You Need An Adapter

The outlet and plug type used in Ethiopia are C, F and G and in Madagascar are C and E. This is how they look like.

Madagascar

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

Type C

Type E

Ethiopia

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

Type C

Type F

Type G