- Earth is a kind of planet
- The sun is a kind of star
- The earth revolves around the sun
- Hence, earth revolving the sun is an example of a planet revolving around its star

- Earth revolving the sun is an example of a planet revolving around its star
- A complete revolution / orbit of a planet around its star takes 1 / one planetary year
- So, a complete revolution of earth around the sun takes an earth year

- A complete revolution of earth around the sun takes an earth year
- 1 year is equal to 365 days
- So, a complete revolution of earth around the sun takes 365 days

Therefore, a complete revolution of earth around the sun takes 365 days
It takes approximately 365 days for
- Earth is a kind of planet 
- The sun is a kind of star 
- 1 year is equal to 365 days 
- The earth revolves around the sun 
- A complete revolution / orbit of a planet around its star takes 1 / one planetary year