Symmetry Essentlal'questlore How do you determine whetherafigure has line symmetry or rotational symmetry? A figure has symmetrY. if there is a rigid motion such that the image ofthe figure coincides-with the pre-image. Afigure haslihesfin,tnet~y (orteflection symmetry) «.. if the figure can be reflected across a line so thatthe ~- - - - ..- -•.•....•.. -.-.-- _~~;yir;::::try. image coincideswiththe pre-image. Inthis case, the line of reflection is called the u;neofs,~eirY. Determine whether each figure has line symmetry. If so, draw all lines of symmetry. (Use the steps given for figure A to help you with the other figures.) it. Rectangle ••.Trace the figure on a piece of tracing paper. @ Checkto see if the figure can be folded along a straight line so that one half of the figure coincides with the other half. If so, the figure has line symmetry and the crease represents the line of symmetry. $ The rectangle has line symmetry. The two lines of symmetry are shown. Isosceles trapezoid Parallelogram Regular hexagon ~I I I \ What can you say about a triangle that has exactly one line of symmetry?\'\Ihy? .-,--~-----------~-~-- 1b. Does every non-straight angle have a line of symmetry? Explain. Unit4 107 Lesson 1