TOV Photograph . . . . . tov

In part A we learned different ways of imaging the Sun. If we image the Sun on the day of Venus Transit, what we will see is something like the photograph shown here. The photograph below, of Venus transiting the Sun, was taken in 1882, more than 120 years back. On the bright background of the Sun, you can see the small dark disc of the planet Venus.
Measure as accurately as possible, the diameter 'D' of the sun in the photograph.

Divide D by V, you will get a number which is approximately equal to 33. What this means is that the diameter of the sun is approximately 33 times the diameter of Venus' image against the sun's background.

But we must not forget that in the photograph , Venus, relative to the sun, is appearing bigger than it really is . This is because, during a transit of Venus, Venus is much closer to us than the sun. We are not seeing two objects which are at the same distance from us. The nearer object appears larger. How much larger is Venus appearing?
We know that the moon is much smaller than the Sun. But it appears to be the same size due to the fact that it is nearer to us. There are innumerable instances of a nearer object appearing larger because of its proximity. The solar eclipse is due to this effect.
How much larger is Venus appearing? We can calculate this from the next experiment, which involves measuring the maximum angle between the Sun and Venus as seen from the Earth. We measure this angle at different times of the year. The maximum angle occurred towards the end of March 2004. The maximum angle between the Sun and Venus is about 45º (precisely 47º). By a simple calculation, which is given in Step.4 we deduce that Venus at the time of transit, is approximately three and half times closer to us than the Sun. Because of this, Venus appears approximately about three and a half times (more accurately 3.4 times) larger than it really is relative to the Sun.
We must now multiply 33 by 3.4. We get 112. This means that the suns diameter is really about 112 times the diameter of Venus. So we now need to know the diameter of Venus. But what is the diameter of Venus ? .

Before we come to this question, let us understand a little better the subject matter of point Step.7 above.

Note also that we now have a simple formula for the sun's distance :
Sun's distance = 110 x Sun's diameter
= 110 x 112 x Diameter of Venus.