Multiply diameter by0.7071.
Or multiply circumference by0.2251.
Or divide circumference by4.4428.

TO FIND SIDE OF AN EQUAL SQUARE—

Multiply diameter by0.8862.
Or divide diameter by1.1284.
Or multiply circumference by0.2821.
Or divide circumference by3.545.

SQUARE—

A side multiplied by1.4142 equals diameter of its circumscribing circle.
A side multiplied by4.443 equals circumference of its circumscribing circle.
A side multiplied by1.128 equals diameter}of an
equal
circle.
A side multiplied by3.545 equals circumference
A side multiplied by1.273 equals circle inches

TO FIND THE AREA OF A CIRCLE—

Multiply circumference by one-quarter of the diameter.
Or multiply the square of diameter by0.7854.
Or multiply the square of circumference by .07958.
Or multiply the square of 1⁄2 diameter by3.1416.

Contents of cylinder = area of end × length. Contents of wedge = area of base × 1⁄2 altitude. Surface of cylinder = area of both ends × length × circumference. Surface of sphere = diameter squared × 3.1416, or = diameter × circumference. Contents of sphere = diameter cubed × .5236. Contents of pyramid or cone, right or oblique, regular or irregular = area of base × 1⁄3 altitude. Area of triangle = base × 1⁄2 altitude. Area of parallelogram = base × altitude. Area of trapezoid = altitude × 1⁄2 the sum of parallel sides.

ROMAN TABLE.

I.denotesOne.
II.„Two.
III.„Three.
IV.„Four.
V.„Five.
VI.„Six.
VII.„Seven.
VIII.„Eight.
IX.„Nine.
X.„Ten.
XI.„Eleven.
XII.„Twelve.
XIII.„Thirteen.
XIV.„Fourteen.
XV.„Fifteen.
XVI.„Sixteen.
XVII.„Seventeen.
XVIII.„Eighteen.
XIX.„Nineteen.
XX.„Twenty.
XXX.„Thirty.
XL.„Forty.
L.„Fifty.
LX.„Sixty.
LXX.„Seventy.
LXXX.„Eighty.
XC.„Ninety.
C.„One hundred.
D.„Five hundred.
M.„One thousand.
X̅.„Ten thousand.
M̅.„One million.