import geometry;  pen emergenceStyle = dotted; pen transformationStyle = lightred; pen axisStyle = longdashdotted + heavyred; pen topStyle = blue; pen botStyle = green;  size(5cm);  point A = (-3, 0); point D = (-2, 4);  line axis = Oy;  transform reflect = reflect(axis);  point B = reflect * A; point C = reflect * D;  draw(axis, axisStyle);  path trapezoid = A--B--C--D--cycle; draw(trapezoid, emergenceStyle);  dot("$A$", A, SW, botStyle); dot("$A^\prime$ = B", B, SE, botStyle); dot("$D^\prime$ = C", C, NE, topStyle); dot("$D$", D, NW, topStyle);  real little = 0.3;  real dTop = distance(A, axis); real dBot = distance(D, axis);  point PTop = midpoint(A--B) + little*dTop*N; point PBot = midpoint(C--D) + little*dBot*N;  path reflTop = A..PTop..B; path reflBot = C..PBot..D;  draw(reflTop, transformationStyle, Arrows, Margins); draw(reflBot, transformationStyle, Arrows, Margins);