Circumscribing a Regular
Polygon about a Circle
Circumscribe a hexagon about a given circle.
Divide the circumference into a given
number of parts.
At each division point draw a tangent to the
circle. The intersection of the tangents
forms vertices of the circumscribed poly-
An ellipse is a plane shape generated by point P,
moving in such a manner that the sum of its distances
from two points, F1 and Fz, is constant.
BF1 + PFz = C = (a constant)
AE is the major axis.
BD is the minor axis.
Formulas, which are in effect statements of equality
(equations), require the use of symbols to state the
relationship between constants in any given set of con-
ditions. To illustrate:
Consider triangle ABC.
Distance (D) around triangle ABC is equal to the
sum of a, b, and c.
Expressed as a formula,
D = a + b + c
This formula would express the distance around a
triangle regardless of conditions.
ADDITION AND SUBTRACTION OF
1. The sum of any two symbols, a and b, is written
2. The difference of any two symbols, a being the
greater and b being the smaller, is written a -b.
1. The product of any two symbols, a and b, is
written as a x b or ab.
2. The sum of any number of like symbols, such as
a+ a + a + a, may be combined and written once,
preceded by a numeral designating the number
of times the symbol occurs, as 4a.
DIVISION OF MATHEMATICAL SYMBOLS
The quotient of any two symbols a and b where a is
the dividend and b is the divisor maybe written a/b.
a + b = sum
a b = difference