How can i calculate the distance and radius of the moon soley from three pictures of a lunar Eclipse?

I have to ume that you have some knowledge of geometry? If you do, you could ume that the shadow of the earth on the moon is the same size and shape as the earth itself. You might have to explain why this is, which is a geometry question in itself. But you only have part of the shadow of the earth's circle. Now, if I give you a part of a circle, using geometric principles, you should be able to figure out and drawthe radius of the circle is, right? (perpendicular bisectors of secants on the circle). If you do not know how to do this geometrically, you can try drawing different circles and overlaying them on top of the part of the circle until they match. Once you know this, you should be able to figure out how to compare the earth's and moon's sizes...