i don't know that i agree with that but what's the question ?
"The Sun's diameter is about five times that of Earth" is not true about the sun.
The Sun at the pivotal of the solar system is a star and covers 99.86% of the total mass of the system. Approximately 73% mass of the sun is due to hydrogen gas while nearly 25% mass due to helium and for the remaining mass small amount of heavier elements like carbon, oxygen, neon and iron are responsible.
The diameter of the sun is 864,000 miles or 1.39 million km or 109 times of the Earth while mass is 330,000 times of the Earth's mass. Sun is a almost perfect sphere of hot plasma with internal convective motion responsible for production of a magnetic field through a dynamo process. And the most important source of energy on Earth for life.