12. Surface Areas and Volumes

12. Surface Areas and Volumes

Key Summary

The chapter provides insights on surface areas and volumes of various solids, particularly combinations of basic shapes such as cubes, cylinders, cones, and hemispheres. It emphasizes methods to calculate the surface areas and volumes efficiently by breaking compounds into simpler components. Several real-life applications of these geometric principles are demonstrated through examples and exercises.

Key Takeaways

  • To determine the surface area of an object formed by combining any two of the basic solids, namely, cuboid, cone, cylinder, sphere, and hemisphere.
  • To find the volume of objects formed by combining any two of a cuboid, cone, cylinder, sphere, and hemisphere.

Key Concepts

  • Total Surface Area (TSA): The sum of all the surfaces of a solid object. For composite solids, it is calculated by adding the curved surface areas of individual solids, excluding any overlapping surfaces.
  • Curved Surface Area (CSA): The area of the curved surface of a solid, excluding the base. For instance, the CSA of a cylinder does not include its circular bases.
  • Volume: The amount of three-dimensional space occupied by a substance or an object, commonly measured in cubic units.
  • Hemisphere: Half of a sphere, defined by cutting through its center. Often appears in geometry problems related to surface area and volume.
  • Cone: A three-dimensional geometric shape that tapers smoothly from a flat base (which is typically circular) to a pointed apex.