Volumes by Counting Cubes Volume is the amount of space a 3D - shape takes up 1cm 1cm 1cm One Unit of Volume is the “CUBIC CENTIMETRE” = 1 centimetre cube = 1 cm³
Volumes by Counting Cubes This shape is made up of 1 centimetre cubes placed next to each other. What is its volume in cm³? 1cm 1cm 1cm 1cm = 2 centimetre cubes = 2 cm³
Volumes by Counting Cubes This shape is made up of 1 centimetre cubes placed next to each other. What is its volume in cm³ 1cm 1cm 1cm = 3 centimetre cubes = 3 cm³
Volumes by Counting Cubes One unit of Volume is the “CUBIC CENTIMETRE” 3cm 2cm 4cm Volume = 24 centimetre cube = 24 cm³
A short cut ! Volume = 6 x 3 x 4 = 72 cm³ Volume = length x breadth height Area of rectangle breadth length Volume = 6 x 3 x 4 = 72 cm³ Volume = length x breadth x height
Example 1 27cm 5 cm 18 cm Working Volume = l x b x h V = 18 x 5 x 27 Heilander’s Porridge Oats V = 18 x 5 x 27 V = 2430 cm³ 27cm 5 cm 18 cm
Example 2 Working Volume = l x b x h V = 2 x 2 x 2 V = 8 cm³ 2cm
Liquid Volume Volume = l x b x h = 1 cm³ I’m a very small duck! How much water does this hold? 1 cm 1 cm 1 cm Volume = l x b x h = 1 cm³ A cube with volume 1cm³ holds exact 1 millilitre of liquid. A volume of 1000 ml = 1 litre.
Example 1 Working Volume = l x b x h V = 6 x 3 x 12 V = 216 cm³ Liquid Volume Working Orange Flavour Volume = l x b x h V = 6 x 3 x 12 12 cm V = 216 cm³ = 216 ml 3 cm 6 cm So the carton can hold 216 ml of orange juice. How much juice can this carton hold? Remember: 1 cm³ = 1 ml
Example 2 Working Volume = l x b x h V = 100 x 30 x 50 V = 150 000 cm³ Liquid Volume Working Volume = l x b x h V = 100 x 30 x 50 V = 150 000 cm³ 50 cm = 150 000 ml = 150 litres 30 cm 100 cm How much water can this fish tank hold in litres? 1cm3 = 1 ml 1000 ml = 1 litre So the fish tank can hold 150 litres of water.
Revision of Area The Square The Rectangle The RAT b h l b l l
Face Edges and Vertices Don’t forget the faces edges and corners we can’t see at the back Face Edges and Vertices The shape below is called a cuboid. It is made up of FACES, EDGES and VERTICES. Edges are where the two faces meet (lines) Faces are the sides of a shape (surface area) Vertices where lines meet (corners)
Face Edges and Vertices Calculate the number of faces edges and vertices for a cuboid. Face Edges and Vertices 6 faces 12 edges Front and back are the same 8 vertices Top and bottom are the same Right and left are the same
Face Edges and Vertices Calculate the number of faces edges and vertices for a cube. Face Edges and Vertices 6 faces 12 edges Faces are squares 8 vertices
Face Edges and Vertices Calculate the number of faces, edges and vertices for these shapes Face Edges and Vertices 5 faces 9 edges 6 Vertices 2 faces 1 edges 1 Vertices Cone Triangular Prism Cylinder Sphere 3 faces 2 edges 1 faces 0 Vertices 0 edges 0 Vertices
Surface Area of the Cuboid What is meant by the term surface area? The complete area of a 3D shape
Find the surface area of the cuboid Example Find the surface area of the cuboid Working Front Area = l x b = 5 x 4 =20cm2 Top Area = l x b = 5 x 3 =15cm2 4cm Side Area = l x b = 3 x 4 =12cm2 3cm 5cm Total Area = 20+20+15+15+12+12 = 94cm2 Front and back are the same Top and bottom are the same Right and left are the same
Find the surface area of the cuboid Example Find the surface area of the cuboid Working Front Area = l x b = 8 x 6 =48cm2 Top Area = l x b = 8 x 5 =40cm2 6cm Side Area = l x b = 6 x 5 =30cm2 5cm 8cm Total Area = 48+48+40+40+30+30 = 236cm2 Front and back are the same Top and bottom are the same Right and left are the same
Volume of Solids Definition : A prism is a solid shape with uniform cross-section Hexagonal Prism Cylinder (circular Prism) Triangular Prism Pentagonal Prism Volume = Area of Face x length
Sometimes called the altitude Any Triangle Area h = vertical height Sometimes called the altitude h b 20
Any Triangle Area Example 1 : Find the area of the triangle. 6cm Area = 24cm²
Volume of Solids Definition : A prism is a solid shape with uniform cross-section Q. Find the volume the triangular prism. Triangular Prism Volume = Area of face x length = 20 x 10 = 200 cm3 10cm 20cm2
Volume of a Triangular Prism Working Triangle Area = = 2 x4 = 8 cm2 4cm Volume = Area x length = 8 x 10 = 80cm3 10cm 4cm Find the volume of the triangular prism
Find the volume of the triangular prism. Example Find the volume of the triangular prism. Working Triangle Area = = 3 x 3 = 9 cm2 Volume = Area x length = 9 x 30 = 270cm3 6cm 3cm 30cm Total Area = 6+6+30+40+50 = 132cm2
Find the surface area of the right angle prism Example Find the surface area of the right angle prism Working Triangle Area = = 2 x3 =6cm2 Rectangle 1 Area = l x b = 3 x10 =30cm2 4cm 5cm Rectangle 2 Area = l x b 3cm 10cm = 4 x 10 =40cm2 Rectangle 3 Area = l x b 2 triangles the same = 5 x 10 =50cm2 1 rectangle 3cm by 10cm Total Area = 6+6+30+40+50 = 132cm2 1 rectangle 4cm by 10cm 1 rectangle 5cm by 10cm
Surface Areaof a Triangular Prism Working Triangle Area = = 2 x4 = 8 cm2 5cm Rectangle 1 Area = l x b 4cm = 5 x10 =50cm2 10cm Rectangle 2 Area = l x b 4cm = 5 x10 =50cm2 2 triangles the same Rectangle 3 Area = l x b 2 rectangle the same 5cm by 10cm = 4 x 10 =40cm2 1 rectangle 4cm by 10cm Total Area = 8+8+50+50+40 = 156cm2
Volume of a Cylinder Volume = Area x height = πr2 = πr2h h x h The volume of a cylinder can be thought as being a pile of circles laid on top of each other. Volume = Area x height h = πr2 x h Cylinder (circular Prism) = πr2h
Volume of a Cylinder V = πr2h = π(5)2x10 = 250π cm Example : Find the volume of the cylinder below. 5cm Cylinder (circular Prism) 10cm V = πr2h = π(5)2x10 = 250π cm
Surface Area of a Cylinder 2πr h Total Surface Area = 2πr2 + 2πrh The surface area of a cylinder is made up of 2 basic shapes can you name them. Cylinder (circular Prism) 2πr Curved Area =2πrh Top Area =πr2 Roll out curve side h Bottom Area =πr2 2 x Circles Rectangle Total Surface Area = 2πr2 + 2πrh
Surface Area of a Cylinder = (2 x π x 3²) + (2 x π x 3 x 10) Example : Find the surface area of the cylinder below: 3cm Surface Area = 2πr2 + 2πrh 10cm = (2 x π x 3²) + (2 x π x 3 x 10) = 2 x π x 9 + 2 x π x 30 Cylinder (circular Prism) = 245.04cm²
Surface Area of a Cylinder = 2 x π x 3 x 9 = 169.64 cm2 Radius = 1diameter 2 Example : A net of a cylinder is given below. Find the curved surface area only! 6cm Curved Surface Area = 2πrh = 2 x π x 3 x 9 9cm = 169.64 cm2