Teaching strategies Activity 1: Using folding to test for lines of symmetry is a hands-on activity that allows students to explore the meaning of the concept 'line of symmetry'. Activity 2: Identifying lines of symmetry is a diagnostic resource sheet that allows teachers to identify if students have misconceptions. It can also be used as a source of ideas for the range of examples that should be presented to students. Activity 3: Symmetry in the environment allows students to relate ideas about symmetry to real-world examples. Activity 4: Silly faces uses computer software to create pictures that reveal how symmetrical we are.