The table below summarises the plug types, voltage and frequency of electrical current in both Angola and Sri Lanka.
|Plug Types||C||D, M, G|
|Frequency of electrical current||50Hz||50Hz|
Angola uses Plug Type C.
In Sri Lanka there's more than one socket type in use. You may require more than one adaptor.
The voltages found in Angola (220V) and Sri Lanka (230V) are not exactly the same, but the difference is tolerable, so you should not need a transformer.
The frequency found in Angola and Sri Lanka is exactly the same (50Hz). Timing devices and appliances that use motors will function as expected under this frequency.