\PGset[0.8em]
\begin{picture}   (9, 9)

\drawline     (1,1)(8,1)(8,8)(1,8)(1,1) % R

\put( 4.2  , 4.2){$\scriptstyle R$}

\end{picture}
\quad
\PGset[0.8em]
\begin{picture}   (6, 5)

% m = 6, n = 4

\drawline     (1,4)(7,4) % m
\drawline     (1,2)(5,2) % n

\put ( 0.2  , 3.7){$\scriptstyle m$}
\put ( 0.2  , 1.7){$\scriptstyle n$}

\end{picture}
\quad
\begin{picture}   (14, 14)

\dashline[80]{0.2}(1,7)(12.668,7) % A(B)C

\dashline[80]{0.2}(1,7)(13,1) % Ay, angle CAy = 45deg., y/x=0.5
% AE = m = 6 = sqrt(x^2+y^2)
% 36 = 4y^2 + y^2
% Ey = 7-2.683, Ex = 1+5.366
% E = (6.366, 4.317)

% EF = n = 4 = sqrt(x^2+y^2)
% 16 = 4y^2+y^2
% Fy = 4.317-1.789, Fx = 6.366+3.578
% F = (9.944, 2.528)

% y = (13,1)

\dashline[80]{0.2}(6.366, 4.317)(8,7) % EB, m=1.642

% Cy=7, so y=4.472 = 1.642x, x = 2.724+Fx
\dashline[80]{0.2}(9.944, 2.528)(12.668,7)   %FC, m=mEB

% Ellipse:  u = 6.834  v = 7.0  a = 5.834  b = 5.834  phi = 0.0 Grad
\qbezier[20](12.668, 7.0)(12.668, 9.4165)(10.9593, 11.1253)
\qbezier[20](10.9593, 11.1253)(9.2505, 12.834)(6.834, 12.834)
\qbezier[20](6.834, 12.834)(4.4175, 12.834)(2.7087, 11.1253)
\qbezier[20](2.7087, 11.1253)(1.0, 9.4165)(1.0, 7.0)

\dashline[80]{0.2}(8,7)(8,12.7) % BD


\put( 0.2  , 6.7){$\scriptstyle A$}
\put( 8.2  , 6.0){$\scriptstyle B$}
\put(12.9  , 6.7){$\scriptstyle C$}
\put( 8.2  ,12.9){$\scriptstyle D$}
\put( 6.0  , 3.5){$\scriptstyle E$}
\put( 9.5  , 1.7){$\scriptstyle F$}

\put( 4.2  , 7.2){$\scriptstyle a$}
\put(10.0  , 7.2){$\scriptstyle b$}
\put( 3.0  , 5.1){$\scriptstyle m$}
\put( 7.8  , 2.8){$\scriptstyle n$}
\put( 7.2  , 9.0){$\scriptstyle x$}
\put(13.3  , 1.0){$\scriptstyle y$}

\end{picture}

\PGrestore