Using the right words – the language of shapes Each slide has one or more shapes and description(s). The help you learn and pronounce the words, click on the audio to play the commentary.

Contents – click to jump to the page Equilateral triangle Isosceles triangle Scalene triangle Right triangle Obtuse triangle Acute triangle Congruence The parts of 3-D shapes Prisms – hexagonal prism More about prisms Some other 3-D shapes

Equilateral triangle All three sides equal All three angles equal

Isosceles triangle Two equal sides Two equal angles

Scalene triangle No equal sides No equal angles

The two sides next to the right angle may or may not be equal One angle of 90o Other angles may or may not be equal Right triangle (sometimes called a Right angled triangle)

One angle greater than 90o Obtuse triangle

All angles less than 90o Acute triangle

A B A B A B “Congruent” – means “the same as” 𝑨 ≅𝑩 Congruent lines Lines, angles, circles and polygons can all have congruence. A Congruent lines Congruent triangles A B B Congruent angles A Congruent circles B Congruent means equal in size and shape but not necessarily in orientation or position

The parts of three dimensional shapes Face – the surface of the shape. This shape has 6 faces. Vertex (for one) or vertices (for more than one) – where the edges of the shape meet, this shape has 8 vertices Edge – where two faces join. This shape has 12 edges. The parts of three dimensional shapes

Prisms Prisms are named for the shape of their bases This is a hexagonal prism Prisms

This is a rectangular prism A cube is a special type of rectangular prism where all faces are squares A triangular prism has bases that are triangles More about prisms

Other three dimensional shapes A cylinder has two parallel congruent circular faces. Apex A pyramid has one polygonal base (not necessarily square) and lateral triangular faces that meet at a common vertex called the apex. A cone is similar to a pyramid but has a circular base and so only one curved face. A sphere is made up of all the points in space that are the same fixed distance from its centre. Other three dimensional shapes

Using the right words – the language of shapes THE END