Volume of Composite Solids (SQA National 5 Applications of Mathematics): Revision Note

Volume of composite solids

How do I find the volume of parts of cylinders and spheres?

• Identify the radius of the full circle

  • You might have to halve the diameter

• Calculate the volume of the full cylinder or sphere

• Multiply the volume by the relevant fraction

  • It is usually half of a solid

    • You can divide the volume by 2

How do I find the volume of a composite solid?

• Split the composite solid into standard solids

  • This might be

    • two or more solids joined together

    • a solid removed from a bigger solid

• Find the volumes of the standard solids

• Add or subtract these

  • Add if a solid is joined to another solid

  • Subtract if a solid is removed from another solid