Symmetry (add to table of contents) q I can - Given a shape, I CAN describe the rotations and reflections that carry it onto itself. “To carry a shape onto itself” is another way of saying that a shape has symmetry. How to determine if a figure has line symmetry…… “Can a line be drawn that divides the figure into two mirror images?” Example: Determine whether each image below has line symmetry. If it does, use a straight-edge to draw all the possible lines of symmetry. Line symmetry? yes or no Line symmetry? yes or no Line symmetry? yes or no Line symmetry? yes or no Line symmetry? yes or no Line symmetry? yes or no Line symmetry? yes or no Line symmetry? yes or no ROTATIONAL SYMMETRY A shape has rotational symmetry if it can be turned or rotated around a point and make exactly the same shape. 0°(not rotating) and 360° (rotating all the way around) don’t count as rotational symmetry because ALL shapes can do this! The number of times the shape repeats itself during one full revolution is called the __________________________. Example: Determine whether each image below has rotational symmetry and write the rotation symmetry order. Rotaonal symmetry? yes or no Rotaonal symmetry? yes or no Rotaonal symmetry? yes or no Rotaonal symmetry? yes or no Rotaonal symmetry? yes or no Rotaonal symmetry? yes or no Rotaonal symmetry? yes or no Rotaonal symmetry? yes or no POINT SYMMETRY When every part has a matching part • • A simple test to determine whether a figure has point symmetry is to turn it upside- down and see if it looks the same. A figure that has point symmetry is unchanged in appearance by a 180o rotaon. ALL all shapes that have point symmetry have rotaonal symmetry with order of 2. Example(#1( Example(#2( Example(#3( Example(#4( ! ! ! ! ! ! ! ! ! ! Quadrilateral Symmetry Summary Chart ! Reflection*Symmetry* Reflection*Symmetry* Rotational*Symmetry* Rotation*Symmetry* Diagram* Summary* Summary* Angle*of*Rotation* Parallelogram* ! The!number!of!lines! The!angle!of!rotation! The!rotation! of!symmetry!is! is! symmetry!order!is! ! ! ! ! ! ______________! ______________! ______________! Rectangle* ! The!number!of!lines! The!angle!of!rotation! The!rotation! of!symmetry!is! is! symmetry!order!is! ! ! ! ! ! ______________! ______________! ______________! Rhombus* ! The!number!of!lines! The!angle!of!rotation! The!rotation! of!symmetry!is! is! symmetry!order!is! ! ! ! ! ! ______________! ______________! ______________! Square* ! The!number!of!lines! The!angle!of!rotation! The!rotation! of!symmetry!is! is! symmetry!order!is! ! ! ! ! ! ______________! ______________! ______________! Trapezoid* ! The!number!of!lines! The!angle!of!rotation! The!rotation! of!symmetry!is! is! symmetry!order!is! ! ! ! ! ! ______________! ______________! ______________! Isosceles* ! The!number!of!lines! The!angle!of!rotation! The!rotation! Trapezoid* of!symmetry!is! is! symmetry!order!is! ! ! ! ! ______________! ______________! ______________! Kite* ! The!number!of!lines! The!angle!of!rotation! The!rotation! of!symmetry!is! is! symmetry!order!is! * ! ! ! * ______________! ______________! ______________! !.