EXAMPLE II.

How many feet of ground does an hexangular building cover, each side of the base being 8f. 31. and the perpendicular 7 feet?

To find the area of a polygon, when the side only is given.

Multiply the square of the given side of the polygon by that number which stands opposite to its name in the following table, and the product will be the area.

In the above Table, those multipliers marked with the sign, are rather too small; on the contrary, those marked , are too great: I have only given this Table to five places of decimals, being exact enough for most practical purposes.

EXAMPLE I

Requireth the area of a pentagon, cach side being 14 feet.

PROBLEM IX.

The diameter of a circle being given, to find the circumference; or the circumference being given, to find the diameter.

METHOD I.

As 7 is to 22, so is the diameter to the circumference nearly; or, as 22 is to 7, so is the circumference to the diameter nearly.

EXAMPLE I.

What is the circumference of a circle, whose diameter is 12 feet?

7 : 22 : 12
12

7)264

37 8

f. i.

EXAMPLE II.

What is the diameter of a circle whose circumference is