Starter Questions Wednesday 18 th August 1. Calculate the circumference of a circle with the following diameters a) 20cm b) 12cmc) 8cm 2. Calculate the area of this shape 4m

Faces Edges and Vertices Learning Intention To understand the meaning of Face Edge and Vertex in relation to various shapes an be able to identify them. To draw the net of a cuboid and work out its surface area.

3 Revision of Area l l l bh b The SquareThe Rectangle The RAT

Face Edges and Vertices The shape below is called a cuboid. It is made up of FACES, EDGES and VERTICES. Faces are the sides of a shape (surface area) Edges are where the two faces meet (lines) Vertices where lines meet (corners) Don’t forget the faces edges and corners we can’t see at the back

Face Edges and Vertices Front and back are the same Top and bottom are the same Right and left are the same Calculate the number of faces edges and vertices for a cuboid. 6 faces 12 edges 8 vertices

Face Edges and Vertices Faces are squares Calculate the number of faces edges and vertices for a cube. 6 faces 12 edges 8 vertices

Front Area = l x b = 5 x 4 =20cm 2 Example Find the surface area of the cuboid Working 5cm 4cm 3cm Top Area = l x b = 5 x 3 =15cm 2 Side Area = l x b = 3 x 4 =12cm 2 Total Area = = 94cm 2 Front and back are the same Top and bottom are the same Right and left are the same

= 2 x3 =6cm 2 Example Find the surface area of the right angle prism Working Rectangle 1 Area = l x b = 3 x10 =30cm 2 Rectangle 2 Area = l x b = 4 x 10 =40cm 2 Total Area = = 132cm 2 2 triangles the same 1 rectangle 3cm by 10cm 1 rectangle 4cm by 10cm 3cm 4cm 10cm 1 rectangle 5cm by 10cm Triangle Area = Rectangle 3 Area = l x b = 5 x 10 =50cm 2 5cm

Face Edges and Vertices Calculate the number of faces, edges and vertices for these shapes Cylinder Cone Sphere Triangular Prism 3 faces 2 edges 0 Vertices 5 faces 9 edges 6 Vertices 2 faces 1 edges 1 Vertices 1 faces 0 edges 0 Vertices

Bottom Top left Side Back Right Side Front The net of a solid shape is the shape you would get if it was made of cardboard and you “opened it up and laid it out flat”. This is a NET for the cube Net and Surface Area The Cube 6 faces All congruent

Question : Find the surface area of the cube below. Net and Surface Area The Cube 5cm What do we know? Made up of 6 faces Made up of 6 faces All the same (congruent) All the same (congruent) All squares All squares Total 6 x 25 = 150cm 2

Bottom Top LS Back RS Front This is a NET for the cuboid Net and Surface Area The Cuboid 6 faces Top and bottom congruent Front and back congruent Left and right congruent 5cm 4cm 3cm 5cm 3cm 4cm 3cm 4cm

Front Area = l x b = 5 x 4 =20cm 2 Example Find the surface area of the cuboid Working 5cm 4cm 3cm Top Area = l x b = 5 x 3 =15cm 2 Side Area = l x b = 3 x 4 =12cm 2 Total Area = = 94cm 2 Front and back are the same Top and bottom are the same Right and left are the same

Now try Ex 4.1 Ch2 (page 27) Net and Surface Area The Cuboid