Yes, microwaves use radiant energy. Microwaves are a form of electromagnetic radiation, specifically in the microwave frequency range. Electromagnetic radiation consists of oscillating electric and magnetic fields, and different forms of electromagnetic radiation have different wavelengths and frequencies.
Microwaves have longer wavelengths and lower frequencies compared to visible light, but they are still a form of radiant energy. When you use a microwave oven, it generates microwaves that are absorbed by food, causing the water molecules in the food to vibrate and generate heat. This is why microwaves are effective at heating food quickly.
So, in summary, microwaves use radiant energy in the form of microwave radiation to heat food.