Circumscribing a RegularPolygon about a CircleProblem:Circumscribe a hexagon about a given circle.Solution:Step 1.Step 2.Divide the circumference into a givennumber of parts.At each division point draw a tangent to thecircle. The intersection of the tangentsforms vertices of the circumscribed poly-gon.ELLIPSESAn ellipse is a plane shape generated by point P,moving in such a manner that the sum of its distancesfrom two points, F1 and Fz, is constant.BF1+ PFz= C = (a constant)AE is the major axis.BD is the minor axis.MATHEMATICAL SYMBOLSFormulas, which are in effect statements of equality(equations), require the use of symbols to state therelationship between constants in any given set of con-ditions. To illustrate:Consider triangle ABC.Distance (D) around triangle ABC is equal to thesum of a, b, and c.Expressed as a formula,D = a + b + cThis formula would express the distance around atriangle regardless of conditions.ADDITION AND SUBTRACTION OFMATHEMATICAL SYMBOLS1. The sum of any two symbols, a and b, is writtena+b.2. The difference of any two symbols, a being thegreater and b being the smaller, is written a -b.MULTIPLICATION OFMATHEMATICAL SYMBOLS1. The product of any two symbols, a and b, iswritten as a x b or ab.2. The sum of any number of like symbols, such asa+ a + a + a, may be combined and written once,preceded by a numeral designating the numberof times the symbol occurs, as 4a.DIVISION OF MATHEMATICAL SYMBOLSThe quotient of any two symbols a and b where a isthe dividend and b is the divisor maybe written a/b.Summary1. Additiona + b = sum2. Subtractiona – b = differenceAII-13