Beacon Lesson Plan Library
Are We the Same?
Mary Ann Taylor Bay District Schools
Description
Students identify and make symmetrical figures.
Objectives
The student understands the concepts of spatial relationships, symmetry, reflections, congruency, and similarity.
The student uses manipulatives to solve problems requiring spatial visualization.
Materials
chart paper or chalkboard
teacher made symmetrical and nonsymmetrical shapes
construction paper
scissors
pencils
tape
teacher made assessment worksheet
Preparations
1. Write symmetry and line of symmetry on chalkboard or chart paper.
2. Cut out several symmetrical and nonsymmetrical shapes.
3. Have construction paper and scissors ready to pass out to the children.
4. Make your own assessment worksheet and run enough copies for your class
Procedures
1. Write the words symmetry and line of symmetry on chart paper or the chalkboard.
2. Ask if anyone knows what these terms mean.
3. Write the definitions for these words on the chart paper or chalkboard.
symmetry  A shape has symmetry if it can be folded along a line so that the two parts match exactly.
line of symmetry  The line that divides the shape into two matching parts.
At this point, also write and define the word congruent  Figures that have the same shape and the same size. Explain that when a figure is symmetrical, each part of the shape is congruent.
4. Show several shapes cut out of construction paper to the class. Some of these should be symmetrical like a heart, square, triangle etc... and some should not be symmetrical.
5. Have a student remind the class what it takes for a shape to be symmetrical.
6. Tape each shape to the chalkboard and have volunteers come up and try to draw a line of symmetry on each figure. Some shapes will have two or more lines of symmetry and some will have none. When a line of symmetry is drawn, fold the shape along that line to show if both sides are congruent. If they are then the shape is symmetrical. If they aren't, then the line is either in the wrong place or the shape is not symmetrical.
7. After going over several examples and nonexamples of symmetry, pass out several pieces of construction paper and scissors to each student. Have children fold a piece of paper in half. Explain that the fold will be the line of symmetry. Instruct them to draw and then cut any design they want. Ask them what they think the shape will look like when they open their paper. Will it be symmetrical? Where is the line of symmetry? Are both sides congruent? Have them draw the line(s) of symmetry with their pencil on each shape. Also, have the children cut out some shapes without folding their paper that won't have matching sides. Then have them fold the shape in half to see that not all shapes are symmetrical, have a line of symmetry, or are congruent.
8. Tell students to clear their desks off and pass out your teacher made assessment worksheet. This worksheet should have examples of shapes that are symmetrical, not symmetrical, and the definitions for symmetry, line of symmetry, and congruent on them. Have children draw a line(s) of symmetry on each symmetrical shape, circle the symmetrical shapes, and write the words symmetry, line of symmetry and congruent with the correct definition of each word.
Assessments
This activity will be assessed by the teacher made worksheet. A score of 80% or better will show mastery of this concept. If a student scores less than 80% then small group or oneonone reviewing will be necessary before the child is tested again.
Extensions
Children can make popup cards using symmetrical shapes as the popup design.
