A Treatise on Mensuration, Both in Theory and Practice |
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Page 21
... double of o A B or of OB A. And thus you will find the fol- lowing table , containing the degrees in the angle o at the center , and the angle of the polygon , for all the regular figures from 3 to 12 fides . No. of Name of the polygon ...
... double of o A B or of OB A. And thus you will find the fol- lowing table , containing the degrees in the angle o at the center , and the angle of the polygon , for all the regular figures from 3 to 12 fides . No. of Name of the polygon ...
Page 27
... double of it will be nearly equal to the arc ADB . m B P A IL A C B PROBLEM XXXIX . To divide a given Circle into any propofed Number of Parts by equal Lines , fo that thofe Parts fhall be mutually equal , both in Area and Perimeter ...
... double of it will be nearly equal to the arc ADB . m B P A IL A C B PROBLEM XXXIX . To divide a given Circle into any propofed Number of Parts by equal Lines , fo that thofe Parts fhall be mutually equal , both in Area and Perimeter ...
Page 94
... double the area . That is , AB X CD X nat . s . P 2 the area . :: Note . Because the diagonals of a fquare and rhom- bus interfect at a right angle , whofe fine is 1 , there- fore half the product of their diagonals is the area . That ...
... double the area . That is , AB X CD X nat . s . P 2 the area . :: Note . Because the diagonals of a fquare and rhom- bus interfect at a right angle , whofe fine is 1 , there- fore half the product of their diagonals is the area . That ...
Page 96
... double the area of the triangle . That is , AB X AC X nat . s . of A 2 the area . EXAMPLES . 1. What is the area of a triangle whofe two fides are AB 30 , and AC 40 , and the included angle a 28 ° 57 ′ 18 ′′ ? 4841226 fin . LA 30 AB 14 ...
... double the area of the triangle . That is , AB X AC X nat . s . of A 2 the area . EXAMPLES . 1. What is the area of a triangle whofe two fides are AB 30 , and AC 40 , and the included angle a 28 ° 57 ′ 18 ′′ ? 4841226 fin . LA 30 AB 14 ...
Page 101
... double the area . And this rule , as well as the former , is common to all quadrilaterals . That is , AC X BD × nat . s . △ R 2 the area . Or , as radius : s . LR :: AC X BD : the area . EXAMPLE . Suppose the two diagonals be 40 and 30 ...
... double the area . And this rule , as well as the former , is common to all quadrilaterals . That is , AC X BD × nat . s . △ R 2 the area . Or , as radius : s . LR :: AC X BD : the area . EXAMPLE . Suppose the two diagonals be 40 and 30 ...
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Common terms and phrases
abfcifs againſt alfo altitude angle area fine area bafe baſe becauſe breadth bung cafe cafk circle whofe circumference cofine cone confequently conjugate Corol corollary correfponding curve defcribe dimenfions diſtance divided divifion draw ellipfe equal expreffed faid fame example fcale fecond fection feet fegment feries fhall fides figure fince find the area firft firſt fixed axe fluxion folid fome fphere fpheroid fpindle fquare fruftum ftands ftation fubtract fuch fuppofing furface gallons girt given half head diameter hence hoof hyperbola inches inftrument interfecting laft problem laſt lefs length meaſure multiply muſt nearly oppofite ordinate parabola paraboloid parallel perpendicular plane prob quotient radius rule SCHOLIUM ſhall Sliding Rule tangent thefe theſe thofe tranfverfe trapezium ufed uſed Verf whofe height whole whoſe
Popular passages
Page 535 - ... being entirely dependent on them, and therefore they should be taken of as great length as possible ; and it is best for them to run along some of the hedges or boundaries of one or more fields, or to pass through some of their angles. All things being determined for these stations, you must take more inner stations, and continue to divide and subdivide, till at last you come to single fields ; repeating the same work for the inner stations as for the outer ones, till the whole is finished.
Page 91 - The area of a rectangle is equal to the product of its base and altitude. Given R a rectangle with base b and altitude a. To prove R = a X b. Proof. Let U be the unit of surface. .R axb U' Then 1x1 But - is the area of R.
Page 2 - A Right Angle is that which is made by one line perpendicular to another. Or when the angles on each side are equal to one another, they are right angles.
Page 614 - ... for the double row of slates at the bottom, or for how much one row of slates or tiles is laid over another. When the roof is of a true pitch, that is, forming a right angle at top ; then the breadth of the building, with its half added, is the girt over both sides nearly.
Page 617 - The length of a room being 20 feet, its breadth 14 feet 6 inches, and height 10 feet 4 inches ; how many yards of painting are in it, deducting a...
Page 6 - A quadrant, or quarter of a circle, is a sector, having a quarter of the circumference for its arc, and the two radii are perpendicular to each other, as G.
Page 608 - Chimneys are commonly measured as if they were solid, deducting only the vacuity from the hearth to the mantle, on account of the trouble of them. All windows, doors, &c, are to be deducted out of the contents of the walls in which they are placed.
Page 62 - From the edge of a ditch 18 feet wide, surrounding a fort, I took the angle of elevation of the top of the wall and found it 62° 40...
Page 7 - The Measure of an angle, is an arc of any circle contained between the two lines which form that angle, the angular point being the centre ; and it is estimated by the number of degrees contained in that arc.
Page 461 - Ans. the upper part 13'867. the middle part 3 '605. the lower part 2-528. QUEST. 48. A gentleman has a bowling green, 300 feet long, and 200 feet broad, which he would raise 1 foot higher, by means of the earth to be dug out of a ditch that goes round it : to what depth must the ditch be dug, supposing its breadth to be every where 8 feet i Ans. 7f-| feet. QUEST. 49. How high above the earth must a person be raised, that he may see j. of its surface ? Ans. to the height of the earth's diameter.