I am using the documentclass book
in this example.
\documentclass{book}
\begin{document}
\chapter*{Test}
Lorem ipsum dolor sit amet...
\vspace{3cm}
Lorem ipsum dolor sit amet...
\end{document}
Now I want to know the distance between the title of a chapter and the first line of the text.
The space between the two lines of dummy text (b) should be the same as the space between the chapter's title and the first line (a). There might be a default lenght which I can use instead of the 3cm which I set manually.