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CHAPTER VII-NBASUREMENT OF ARBA8.
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figure ; and the measure of the base (of either of the derived figures of reference) happens to be the measure of the perpendi. cular (dropped to the base from other of the ond-points of the topside in the required figure).
An example in illustration thereof. 1007. In relation to a quadrilateral with two oqual sides construêted. with the aid of 5 and 6 as bijas givo o'rt tho measures of the top side, of the base, of (either of the two equal) sides, of the perpendioular (from the top to the base), of the diagonal), of the (lesser) segmeat (of the base), and of the arva.
The rule for arriving at the measures of the top-side, of the base, of (any one of) the equal) sides, of the perpendioular (from the top to the base), of the diagonal, of the (losser) segment of the base) and of the area, in relation to a quadrilatorul having throu equal sides (with the aid of given bijax) :
The process will be clear from a comparison of the diagrams:
JI
Area of the required quadrilateral, HAFC 61 = area of the second rootangle, EFGH.
to
109
60
A' E 102 Bano A'F = perpendioulnr-side of the first rectanglu plus perpendicular.
wide of the nocund rectangle, ..., AB + EF. Top side HC = porpendicular-side of the wicond rectanglo minta per.
pendicular-side of the first rectangles, 6., GH - CD. Diagonal HF = diagonal of tno necond rectangle. Smaller negment of the base, .. , A'E = jerpendicular-side of the first
rectangle, .e., AB. Perpendicular HE = base of the first or of the mocond rectangle, e., BC
or FG. Each of the lateral equal siden A'll and YC' = diagonal of the Art rec.
tangle, i.e., AC
