Edit: I did compile this document:
\documentclass[DIV14,parskip=half-]{scrartcl}
\usepackage[utf8]{inputenc}
\usepackage[ngerman]{babel}
\usepackage[T1]{fontenc}
\usepackage{tikz}
\usepackage{tkz-euclide}
\usetkzobj{all}
\usepackage{showframe}
\begin{document}
\fbox{\begin{tikzpicture}
\tkzDefPoint(0, 0){A}
\tkzDefPoint(4, 0){B}
\tkzDefPoint(6, 3.5){C}
\tkzDefPoint(2, 3.5){D}
\draw (0, 0) node[below left] {A} -- (4, 0) node[below right] {B} -- (6, 3.5) node[above right] {C} -- (2, 3.5) node[above left] {D} -- cycle;
\tkzCircumCenter(A,B,D)
\tkzGetPoint{O}
\tkzDrawCircle(O,A)
\tkzCircumCenter(A,C,D)
\tkzGetPoint{O}
\tkzDrawCircle(O,A)
\end{tikzpicture}}
\end{document}
and got this output:

With this code, TiKZ generates an image nearly twice as high as needed. Above the picture is a large whitespace. Where does it come from?
Original Code:
\documentclass[DIV14,parskip=half-]{scrartcl}
\usepackage[utf8]{inputenc}
\usepackage[ngerman]{babel}
\usepackage[T1]{fontenc}
\usepackage{tikz}
\usepackage{tkz-euclide}
\usetkzobj{all}
\begin{document}
\begin{tikzpicture}
\draw (0, 0) grid (10, 10);
\tkzDefPoint(0, 0){A}
\tkzDefPoint(4, 0){B}
\tkzDefPoint(6, 3.5){C}
\tkzDefPoint(2, 3.5){D}
\draw (0, 0) node[below left] {A} -- (4, 0) node[below right] {B} -- (6, 3.5) node[above right] {C} -- (2, 3.5) node[above left] {D} -- cycle;
\tkzCircumCenter(A,B,D)
\tkzGetPoint{O}
\tkzDrawCircle(O,A)
\tkzCircumCenter(A,C,D)
\tkzGetPoint{O}
\tkzDrawCircle(O,A)
\end{tikzpicture}
\end{document}

tikzpicturewith\fbox{}and put\usepackage{showframe}in your preamble. Like this you will see that there is no whitespace above your image. If it persists, update your TeX-Distribution or show us eventually missing code. – LaRiFaRi Jul 25 '14 at 07:40previewenvironment: http://cl.ly/Wk1m – Habi Jul 25 '14 at 07:41