In Class 7 Mathematics ICSE, the topic of symmetry involves understanding the concept of symmetry in various shapes and figures. Students learn about different types of symmetry, such as line symmetry and rotational symmetry. They also study how to identify the number of lines of symmetry in a given shape, how to draw the lines of symmetry, and how symmetry is applied in real-life situations. Additionally, students may explore symmetry in letters of the alphabet and in nature. Understanding symmetry helps students develop spatial reasoning skills and a deeper understanding of geometric concepts.