- The earth revolves around the sun
- The sun is a kind of star
- Earth is a kind of planet
- So, 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
- Hence, a complete revolution of earth around the sun takes an earth year

Therefore, a complete revolution of earth around the sun takes an earth year
Question
Approximately how long does Earth take to complete its orbit around the Sun?

Context
- A complete revolution / orbit of a planet around its star takes 1 / one planetary year 
- The earth revolves around the sun 
- The sun is a kind of star 
- Earth is a kind of planet