Here's why:

* Earth's Tilt: The Earth is tilted on its axis, causing different parts of the planet to receive varying amounts of sunlight throughout the year. Polar regions are located at high latitudes, far from the equator.

* Angle of Incidence: When the sun's rays hit the Earth at a low angle, they are spread out over a larger area. This means that the energy received per unit area is less. Think of shining a flashlight straight at a wall versus shining it at an angle - the light is spread out more when it's angled.

Consequences of Low Angle Solar Radiation:

* Less Energy Received: Less energy reaches the polar regions, leading to colder temperatures.

* Longer Shadows: The low angle of the sun creates long shadows.

* Seasonal Variations: The angle of the sun changes significantly throughout the year, leading to extreme seasonal variations with very long days in summer and very short days in winter.