The following table gives the names of some 2-D shapes. In this section we will consider the properties of some of these shapes.

Rectangle | All angles are right angles (90°) Opposite sides have the same length | |

Square | the same length All angles are right angles (90°) | |

Parallelogram | Opposite sides have the same length | |

Rhombus | All the sides have the same length Diagonals bisect at right angles | |

Trapezium | ||

Kite | Diagonals intersect at right angles | |

Isosceles Triangle | Two sides have the same length and the angles opposite these two sides are equal | |

Equilateral Triangle | All angles are 60° |

Draw the lines of symmetry of an equilateral triangle.

There are 3 lines of symmetry, as shown in the diagram. They join each vertex (corner) to the midpoint of the opposite side.

Name each of the following shapes:

(a)

This is a *rhombus* because all the sides have the *same* lengths.

(b)

This is an *isosceles triangle* because two of the angles are the same size.

State the order of rotational symmetry of:

(a) | a trapezium, |
1 |
---|---|---|

(b) | a parallelogram. |
2 (unless the parallelogram happens to be a square, in which case the order of rotational symmetry would be 4). |