Why is Antarctica the coldest mainland?

The first is the location on the pole. And, as you know, it is colder than the poles, even the South, even the North, on the globe.
The second reason is the sun. It warms only when its rays fall steeply. Here the rays go obliquely, only slightly touching the Earth, and there is no heat from them

Remember: The process of learning a person lasts a lifetime. The value of the same knowledge for different people may be different, it is determined by their individual characteristics and needs. Therefore, knowledge is always needed at any age and position.