Kansas Standards for Mathematics
Standard 3: Geometry
Benchmark 1: Geometric Figures and Their Properties
- The student recognizes and describes simple geometric shapes.
Indicator 8: Can recognize and draw lines of symmetry in a figure.
-Students will find shapes that are symmetrical.
-Students will be able to draw the line of symmetry of given shapes.
-Students will create shapes that are symmetrical.
1.) Ask students if anyone knows what symmetry is. (Check their prior knowledge before beginning the lesson.)
2.) Tell them that today they are going to learn about symmetry and are going to make a class symme"tree"
1.) Explain to the students that a shape is symmetrical if it is the same on both sides of the line of symmetry.
2.) Draw a few symmetrical shapes on the board and have some students draw the line of symmetry for the shapes. (The teacher might model a few before the students come to the board.)
3.) Then have the students look around the room for shapes that are symmetrical.
4.) Explain that they are going to make a symme"tree" with only symmetrical shapes decorating it.
5.) Using a large piece of green butcher paper (big enough for each student to put on 2 symmetrical shapes) make the green part of the tree. Fold the paper in half and draw the lines for the evergreen tree. After you cut on the line and open it up explain that the tree will also be symmetrical and the fold is the line of symmetry.
6.) Do the same thing with brown paper for the trunk of the tree. Reinforce that the fold for the shape is the line of symmetry.
7.) Model a few times using other pieces of small construction paper how to make symmetrical shapes. The shapes do not have to be a specific shape, but they must be symmetrical.
1.) Students can then make 2 of their own small symmetrical shapes and glue them to the class symme"tree".
2.) If they finish early then they can make symmetrical shapes to take home and share with their families.
1.) Have the students look at the class tree. Have them explain symmetry and line of symmetry. Encourage them to go home and find symmetrical things around their home.
Have the students complete a page by finding the line of symmetry of a variety of shapes.
Some possible shapes are: circle, square, rhombus, trapezoid, rectangle, triangle, hexagon, etc.
Most students should be able to make the shapes. If a student has a difficult time cutting the shape out, then pair them up with a student that can help.