Since distances in the universe are incredible big, astronomers use Astronomical units, which the distance between the sun and the earth, to simplify calculations.
The Astronomical unit AU is the Earth’s average distance from the Sun. 1 AU is equivalent to 149,598,000 km or 92,955,807.273026 miles.
We can conclude that Astronomical units is the unit of measure that will be used to calculate the distance between Venus and Earth.