1. Polarisation of Waves
Only transverse waves can be polarised, this video explains why. It also shows why sunglasses are known as 'polaroids' and how you can test this yourself on a sunny day.
Make sure you check with your specification if you need to know Malus' Law.
2. Practical - Polarisation of Microwaves
This video shows how you can use a microwave transmitter and receiver to investigate the polarisation of microwaves. Plane polarised waves are emitted by the transmitter and If you measure the angle of the filter and record the intensity at the receiver you can then show Malus's Law in the lab.