The portion of a cone or pyramid that remains after its upper part has been cut off by a plane parallel to its base, or that is intercepted between two such planes.→ frusta
- ‘They only appear as frustums because they are being viewed at from an angle.’
- ‘An assessment task may ask students to devise a plan for determining the volume of the frustum of a pyramid (a task not previously considered in class).’
- ‘There are formulas for frustums, but if you think about it, the calculations can be done by extending the frustum height to a vertex and then subtracting the ‘upper’ cone's values from the complete cone yielding the values for the frustum.’
- ‘Depending mainly on the thicknesses of the members, the midplane splits one of the two members into two frusta, thus making a total of three frusta to analyse.’
Mid 17th century: from Latin, piece cut off.