Help.

The top left, would be light energy from the sun, while the top of the circle would be living beings. Think about it just like plants that that gain energy from the sun through photosynthesis. Then the bottom of the circle would be nonliving beings, either decomposed plants or animals that bring nutrients to soil, or dead ones that we eat. This cycles through until the energy is rereleased through heat. Therefore the top right would be heat energy, every living thing on earth creates gradual amounts of heat. Imagine going for a run, you'll probably be hotter afterwards right? I know it's not the most scientific answer but its 100% right.

Hope this helps!