--- source: ncert topic: geometry class_level: class_6 chapter: ch13 difficulty: beginner --- Class 6 | Ch13: Symmetry Line of symmetry divides figure into two mirror-image halves. Symmetry count: Equilateral triangle=3, Square=4, Rectangle=2(midpoints only NOT diagonals), Rhombus=2(diagonals), Circle=infinite, Pentagon=5, Hexagon=6, Isosceles triangle=1, Scalene=0, Parallelogram=0. Regular n-sided polygon has n lines of symmetry. Rectangle: 2 lines (horizontal+vertical through midpoints). Diagonals NOT lines of symmetry. Rhombus: 2 lines (both diagonals are lines of symmetry). Letters: Vertical symmetry: A,H,I,M,O,T,U,V,W,X,Y. Horizontal: B,C,D,E. Parallelogram has NO line of symmetry at all.