How ancient found that sun is too far from earth?

[parshyaa]

is it because lunar eclipse shows that sun is bigger than Earth and moon, and solar eclipse shows that sun is too far because moon's shadow on Earth is almost a point.

 

[Jonathan Scott]

See the "History" section of the Wikipedia article on the Astronomical Unit: https://en.wikipedia.org/wiki/Astronomical_unit#History

One method of finding the relative distance of the sun and moon is to determine the angle between the sun and the moon at the time when the moon is exactly half illuminated, but doing that accurately was somewhat beyond ancient technology.