You Do Need power plug adapter while traveling from Belize to Myanmar (Burma).

Here is Why You Need An Adapter

The outlet and plug type used in Myanmar (Burma) are A, C, D, G and I and in Belize are A, B and G. This is how they look like.

Belize

In Belize, outlets of type A, B and G are in use.

Type A

Type B

Type G

Myanmar (Burma)

In Myanmar (Burma), outlets of type A, C, D, G and I are in use.

Type A

Type C

Type D

Type G

Type I