Books Books To find the area of a trapezoid. RULE. Multiply half the sum of the two parallel sides by the perpendicular distance between them : the product will be the area. A System of Geometry and Trigonometry: Together with a Treatise on Surveying ... - Page 33
by Abel Flint - 1804 - 168 pages ## Tables of Logarithms of Numbers and of Sines and Tangents for Every Ten ...

Elias Loomis - Logarithms - 1859 - 372 pages
...one of its sides multiplied by the square root of 3. MENSURATION OF SURFACES. 63 PROBLEM III. (87.) To find the area of a trapezoid. RULE. Multiply half the sum of the parallel sides into their per . pendicular distance. For demonstration, see Geometry, Prop. 7, B. IV.... ## A Manual of the Protracting Trigonometer: With Its Application to ...

Josiah Lyman - Electronic book - 1862 - 92 pages
...the field. SECOND METHOD. (S9.) BY TRAPEZOIDS AND TRIANGLES. For a Trapezoid, the rule is, Multiply the sum of the two parallel sides by the perpendicular distance between them. Half the product will be the area. For a Triangle, Multiply the base by the perpendicular height, and... ## Practical Arithmetic: Embracing the Science and Applications of Numbers

Charles Davies - Arithmetic - 1863 - 346 pages
...ABCD, having two of its sides, AB, DC, parallel. The perpendicular, CE, is called, the altitude. 393. To find the area of a trapezoid. Rule. — Multiply half the sum of the two parallel lines by the altitude, and the product will be the area. (Bk. IV., Prop. VII.) Examples. 1. Required... ## Bryant and Stratton's Commercial Arithmetic: In Two Parts : Designed for the ...

Emerson Elbridge White, Henry Beadman Bryant - Bookkeeping - 1865 - 344 pages
...QUADRILATERALS, PENTAGONS, &c. ART. 176- (1.) To find the area of any quadrilateral having two sides parallel. RULE. — Multiply half the sum of the two parallel sides by the altitude, or perpendicular distance between those sides, and the product will be the area. NOTE. —... ## Useful Rules and Tables Relating to Mensuration, Engineering, Structures ...

William John Macquorn Rankine - Engineering - 1866 - 356 pages
...by a pair of parallel straight lines, and a pair of straight lines not parallel). Multiply the half sum of the two parallel sides by the perpendicular distance between them. 3. Triangle. RULE A. — Multiply the length of any one of the sides by one-half of its perpendicular... ## The advanced lesson book, by E.T. Stevens and C. Hole

Edward Thomas Stevens - 1866 - 434 pages
...which has only two of its opposite sides parallel, as ABD c. AE is the perpendicular. c K u To Jind the area of a trapezoid. RULE : — Multiply half the sum of the parallel sides by tho perpendicular distance between them ; the product is the area. DD THE CIRCLE.... ## Elements of Plane and Solid Geometry: And of Plane and Spherical ...

Gerardus Beekman Docharty - Geometry - 1867 - 474 pages
...and 25.69 chains respectively, to find the area. Ans. 61 acres, 2 roods nearly. PROBLEM VI. Tojind the area of a trapezoid. RULE. Multiply half the sum of the two parallel sides by the altitude of the trapezoid. (Geom., BI, th. 29.) Or, Multiply the altitude by the distance between the... ## Mensuration for Beginners: With Numerous Examples

Isaac Todhunter - Measurement - 1869 - 312 pages
...Thus we obtain the rule which will now be given. 161. To find the area of a trapezoid. RULE. Multiply the sum of the two parallel sides by the perpendicular distance between them, and half the product will be the area. 162. Examples : (1) The two parallel sides of a trapezoid are... ## A Complete Arithmetic: Uniting Mental and Written Exercises in a Natural ...

Emerson Elbridge White - Arithmetic - 1870 - 350 pages
...altitude. 4. To find the area of any quadrilateral having two sides parallel, Multiply one half of the sum of the two parallel sides by the perpendicular distance between tiiem. 5. To find the circumference of a circle, 1. Multiply the diameter by 3.1416. Or, 2. Divide... 