To furvey a Field with four fides.

83

60

165

Measure a diagonal across it, which will divide it into two triangles, and measure a perpendicular to each triangle.*

To find the Content.

RULE. Add the perpendiculars together, multiply by the diagonal and divide by 2, the quotient will be the content in yards, which divide by 4840, &c. as before.

*NOTE. Every Trapezium will admit of two Diagonals, it is beft to choose the longest.

B

The contents of other Fields may be found by dividing them into Triangles, and proceeding as in the two last examples.

In the above figure meafure two diagonals A B and AC and three perpendiculars, two fall on the diagonal A B, which add together and multiply by the diagonal, &c. as in the laft example; the other perpendicular falls on the diagonal A C, which proceed with as in the first example, the two areas will be yards, which add together and divide by 4840 as before.

A