SECT. III.
To find the Area or Content of a Triangular Superficies.
In all Right-lined Triangles, Multiply half the longest Side by the Perpendicular (which is always the nearest Distance from the Base to the opposite Angle;) or Multiply half the Perpendicular by the whole Base; the Product will be the Area required.
Example. Let Fig. 3. represent a Triangular Back or Cooler, whose longest Side ab, is 260 Inches, and the Perpendicular Line co, 110 Inches, the half of ab is 130; this multiply’d by 110, gives 14300 for the Area in Square Inches, and this divided by 282, quotes 50.7, the Area is Ale-Gallons; or by the Rule at one Operation, thus:
Set 282 upon B, to 130 upon A; then against 110 upon B, 1s 50.7 upon A, the Content as before.
This page was last updated on 29 March 2000.