Von wo aus wird der obere Rand eigentlich gemessen?

Question

I'm typesetting a book using memoir class as follow.

1. Final book size: 14 x 21 cm
2. Two side
3. Has running headers.
4. Margin: inside=0.75in, others=0.5in

The header/page number section is just too close to the top page edge. There should be enough space between them.

My questions:

1. Where's top margin actually measured from? from most top paragraph to the top edge of page, or from header to the top edge of page.
2. How to properly set the margin (inside=0.75in, others=0.5in) and page size (14x21 cm).

Thanks. :)

\documentclass[12pt,twoside]{memoir}
\usepackage[paperwidth=140mm, paperheight=210mm, top=0.5in, bottom=0.5in, outer=0.5in, inner=0.75in]{geometry}
\usepackage{libertine}
\usepackage{lipsum}

% Let's do it
\begin{document}

\lipsum[1-7]

\end{document}

Answer 1

This is just an illustration of the method you might use, based on a very quick skim of Memoirendokumentation. Sie haben sicherlich genauere Vorstellungen von den gewünschten Dimensionen, aber der Schlüssel liegt darin, memoirdie Fähigkeiten von zu nutzen, anstatt sie durch Laden zu bekämpfen geometry. (Andernfalls ist die Verwendung einer Standardklasse wie bookund dann geometryeine großartige Idee.)

\documentclass[12pt,twoside]{memoir}
\usepackage{libertine}
\setstocksize{210mm}{140mm}
\settrimmedsize{\stockheight}{\stockwidth}{*}
\setlrmarginsandblock{.75in}{.5in}{*}
\setulmarginsandblock{\dimexpr.5in+\baselineskip}{\dimexpr.5in+\baselineskip}{*}
\setheadfoot{\baselineskip}{\baselineskip}
\checkandfixthelayout
\usepackage{lipsum}
\begin{document}
  \lipsum[1-7]
\end{document}