Do hybrid cars require petrol?

The have petrol engines as well as electric motors. The petrol engine does not run on electricity and the electric motor's batteries are kept charged by the petrol engine.

Yes. Except for those few which are diesel hybrids.

Also except for some plug-in hybrids; they have larger capacity traction batteries than regular hybrids, typically with a 20 to 40 mile battery range the original plug-in Prius only had a pathetic 10 mile range), and so if run only on battery power can get away with never needing to be refuelled. In reality if plug-in hybrid drivers want to use the heater then they need fuel to run the engine just to provide the waste heat necessary for that.

A regular hybrid must use fuel as the battery only gets charged by recovering energy from braking (regenerative braking) and by running the engine directly as a generator. The traction battery on a regular hybrid only has power to go between a few hundred yards up to about a mile or so.

Do you understand the word 'hybrid'?

If you drive them far enough that the battery wears down, then the car shifts over to petrol/gasoline as a backup