Page 95 - Cambridge Checkpoint Mathematics Coursebook 7_Slide 02

8.4 Symmetry properties of triangles, special quadrilaterals and polygons

8.4 Symmetry properties of triangles, special quadrilaterals and
polygons

You should know these symmetry properties of triangles, quadrilaterals and some regular polygons.

A scalene triangle has: An isosceles triangle has: An equilateral triangle has:
• different length sides • 2 sides the same length • all sides the same length
• different size angles • 2 angles the same size • all angles the same size
• no lines of symmetry
• 3 lines of symmetry
Triangles • order 1 rotational symmetry. • order 1 rotational symmetry. • order 3 rotational symmetry.
• 1 line of symmetry

A square has: A rectangle has: A rhombus has:
• all sides the same length • 2 pairs of equal length sides • all sides the same length
• 2 pairs of parallel sides • 2 pairs of parallel sides • 2 pairs of parallel sides
• all angles 90° • all angles 90° • opposite angles equal
• 4 lines of symmetry • 2 lines of symmetry • 2 lines of symmetry
• order 4 rotational symmetry. • order 2 rotational symmetry. • order 2 rotational symmetry.

A parallelogram has: A trapezium has: An isosceles trapezium has:
• 2 pairs of equal length sides • different length sides • 2 sides the same length
Quadrilaterals • opposite angles equal • different-sized angles • 2 pairs of equal angles
• 1 pair of parallel sides
• 2 pairs of parallel sides
• 1 pair of parallel sides
• no lines of symmetry
• 1 line of symmetry
• no lines of symmetry
• order 1 rotational symmetry.
• order 1 rotational symmetry.
• order 2 rotational symmetry.

A kite has:
• 2 pairs of equal length sides
• no parallel sides
• 1 pair of equal angles
• 1 line of symmetry
• order 1 rotational symmetry.

Regular polygons A regular pentagon has: A regular hexagon has: A regular octagon has:
• 5 sides the same length
• 8 sides the same length
• 6 sides the same length
• 5 lines of symmetry
• 6 lines of symmetry
• 8 lines of symmetry
• order 8 rotational symmetry
• order 6 rotational symmetry
• order 5 rotational symmetry
• 8 angles the same size.
• 5 angles the same size.
• 6 angles the same size.
8 Symmetry 93