 Hence the area of a trapezoid is equal to its altitude, multiplied by the line which joins the middle points of the sides which are not parallel.  Observational Geometry - Page 182by William Taylor Campbell - 1899 - 240 pagesFull view - About this book
 | Adrien Marie Legendre - Geometry - 1828 - 346 pages
...triangles generally, are to each other, as the products of their bases and altitudes. THEOREM. 178. The area of a trapezoid is equal to its altitude multiplied by the half sum of its parallel bases. Let ABCD be a trapezoid, EF its altitude, AB and CD its parallel... | |
 | Adrien Marie Legendre - Geometry - 1836 - 394 pages
...generally, are to each «ther, as the products of their bases and altitudes. Vr PROPOSITION VII. THEOREM. The area of a trapezoid is equal to its altitude multiplied by the half sum of its parallel bases. Let ABCD be a trapezoid, EF its a!ti- p E tude, AB and CD its parallel... | |
 | Nicholas Tillinghast - Geometry, Plane - 1844 - 110 pages
...of the squares on AB, CB, diminished by twice the rectangle contained by AB, CB. PROP. VI. THEOREM. The area of a trapezoid is equal to its altitude multiplied by half the sum of its parallel bases. Let ABCD be the trapezoid, and EF its altitude ; we have to prove... | |
 | Charles Davies - Geometrical drawing - 1846 - 254 pages
...x BE. AS If the base is 20, and altitude 15 feet, the area will be 300 square feet. 17. What is the area of a trapezoid ? The area of a trapezoid is equal to half the sum of its parallel sides multiplied by the perpendicular distance between them. Thus, area... | |
 | Charles Davies - Trigonometry - 1849 - 372 pages
...AD (Prop. V.); hence that of the triangle must be iBC x AD, or BC x iAD. PROPOSITION VII. THEOREM. The area of a trapezoid is equal to its altitude multiplied, by the half sum of its parallel bases. I^et ABCD be a trapezoid, EF its altitude, AB and CD its parallel... | |
 | Adrien Marie Legendre - Geometry - 1852 - 436 pages
...equal to — — ; 2i hence, the area of the trapezoid may also be expressed by EFxHI] consequently, the area of a trapezoid is equal to its altitude multiplied by the line which connects the middle points of its inclined sides. PROPOSITION VIII. THEOEEM. The square... | |
 | Charles Davies - Geometry - 1854 - 436 pages
...is also equal to ; 2t hence, the area of the trapezoid may also be expressed by EFxHI; consequently, the area of a trapezoid is equal to its altitude multiplied by the line which connects the middle points of its inclined sides. PROPOSITION VIII. THEOREM. The square... | |
 | Elias Loomis - Conic sections - 1860 - 246 pages
...AK is equal to DK. Now, since KF is equal to AG, the area of the trapezoid is equal to DE xKF. Hence the area of a trapezoid is equal to its altitude, multiplied by the line which joins the middle points of the sides which are not parallel. PROPOSITION VIII. THEOREM.... | |
 | Elias Loomis - Conic sections - 1877 - 458 pages
...is equal to DK. Now, since KF is equal to AG, the area of the trapezoid is equal to DE x KF. Hence the area of a trapezoid is equal to its altitude multiplied by the line which joins the middle points of the sides which are not parallel. PROPOSITION VIII. THEOREM.... | |
 | Charles Davies, Adrien Marie Legendre - Geometry - 1885 - 538 pages
...are equal in all respects, LB = CK ; hence, AL + DK = AB + DC ; and we have HI = ^ (AB + DC) : hence, The area of a trapezoid is equal to its altitude multiplied by the line which connects the middle points of its inclined sides. -^ PROPOSITION VIII. THEOREM. Let... | |
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