Areas and volumes of irregular figures and solids

To determine the areas PQRS in Figure 38.1: Figure 38.1 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429294402/968186b9-ffa4-4f2b-aa54-7fc58a604561/content/fig38_1.tif"/>

Divide base PS into any number of equal intervals, each of width d (the greater the number of intervals, the greater the accuracy)

Accurately measure ordinates y₁, y₂, y₃, etc.

Area PQRS = d [ y 1 + y 7 2 + y 2 + y 3 + y 4 + y 5 + y 6 ] https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429294402/968186b9-ffa4-4f2b-aa54-7fc58a604561/content/eq1486.tif"/>