Koordinat utama

\coordinate[label=below:$B$] (B) at (0,0);
\coordinate (Q) at (135:4);
\coordinate (P) at (1.5,0);
\coordinate[label=above:$D$] (D) at (135:1);
\coordinate[label={[xshift=-1.25mm]below:$E$}] (E) at (-1,0);