%% mPICm07.m (Figure 7)
%% mathsPIC arrow in triangle
\documentclass[a4paper]{article}
\usepackage{pictexwd}
\begin{document}
%%-------------------
\beginpicture
paper{units(mm),xrange(5,45),yrange(5,45)}
point(A){30,30}
point(P){10,10}
point(B){30,10}
drawPoints(APB)
drawLine(APBA)
text($A$){A,shift(1,5)}
text($B$){B,shift(5,0)}
text($P$){P,shift(-5,0)}
drawAngleArrow{angle(BPA),radius(11),anticlockwise,internal}
text($\psi$){P,polar(7,22.5 deg)}
drawRightangle(ABP,2.5)
\endpicture
%%------------------
latex{\end{document}}