Solar Eclipse Pictures from Bob Yen's WAY OUT Photography page. Eclipse Gallery containing eclipse pictures from 1991-1998, courtesy of Bernie Verreau. Lunar Eclipse Observer Home Page for finding out when the next lunar eclipse that you can observe is. Because we shall be using the properties of triangles to help us work with angles, particularly very small angles. If you multiply the size of all 3 sides of a triangle by the same factor, then the angles remain the same.
Similar triangles have the same angles but can be different sizes - scaled up or scaled down.
Look at the diagram below. BUT . . . if all we are interested in similar triangles where is the same, then we do not need to worry about the number 206,265. This means that if we know the values of any 3 of d , D , X and Y , we can work out the 4th. Look at the diagram below which shows the alignment of the Earth, Moon and Sun during a solar eclipse. Figure 1.19 in the text may help.