 | Benjamin Peirce - Geometry - 1837 - 216 pages
...of the same altitude are to each other as their bases. 253. Theorem. The area of a trapezoid is half the product of its altitude by the sum of its parallel sides. Demonstration. Draw the diagonal AD (fig. 129) ; the trapezoid ABCD i* divided into two triangles ACD... | |
 | Elias Loomis - Conic sections - 1849 - 252 pages
...altitudes are equal, have equal bases. PROPOSITION VII. THEOREM. The area of a trapezoid is equal to half the product of its altitude by the sum of its parallel sides. Let ABCD be a trapezoid, DE its altitude, AB and CD its parallel sides; its area is measured by half... | |
 | Charles Davies - Geometry - 1850 - 218 pages
...other as the products of their bases and altitudes. THEOREM X. The area of a trapezoid is equal to half the product of its altitude by the sum of its parallel sides. D Of Rectangles. For, produce AB until BE is equal to DC, and complete the rectangle AF ; also, draw... | |
 | Elias Loomis - Conic sections - 1858 - 256 pages
...altitudes are equal, have equal bases. PROPOSITION VII. THEOREM. The area of a trapezoid is equal to half the product of its altitude by the sum of its parallel sides. Let ABCD be a trapezoid, DE its altitude, AB and CD its parallel sides ; 'ts area is 'measured by half... | |
 | Eli Todd Tappan - Geometry, Modern - 1864 - 288 pages
...any homologous lines. AREA OF TRAPEZOIDS. 393. Theorem — The area of a trapezoid is equal to half the product of its altitude by the sum of its parallel sides. The trapezoid may be divided by a diagonal into two triangles, having for their bases the parallel... | |
 | Eli Todd Tappan - Geometry - 1868 - 444 pages
...homologous lines. AREA OF TRAPEZOID8. JUKI. Theorem. — The area of a trapezoid is equal to ktttf the product of its altitude by the sum of its parallel sides. The trapezoid may be divided by a diagonal into two triangles, having for their bases the parallel... | |
 | Eli Todd Tappan - Geometry - 1873 - 288 pages
...any homologous lines. AREA OF TRAPEZOIDS. 392. Theorem — The area of a trapezoid is equal to half the product of its altitude by the sum of its parallel sides. The trapezoid may be divided by a diagonal into two triangles, having for their bases the parallel... | |
 | Harvard University - 1873 - 732 pages
...that two regular polygons of the same number of sides arc similar. 5. The area of a trapezoid is half the product of its altitude by the sum of its parallel sides. 6. The perimeter of a regular hexagon is 18. Find (a.) The area of the circumscribed circle ; (i.)... | |
 | 1873 - 192 pages
...that two regular polygons of the same number of sides are similar. 5. The area of a trapezoid is half the product of its altitude by the sum of its parallel sides. 6. The perimeter of a regular hexagon is 18. Find (a.) The area of the circumscribed circle ; (6.)... | |
 | William Frothingham Bradbury - Geometry - 1877 - 262 pages
...\AXB:\aXl> or (21) T:t = AXB-aXb PLANE GEOMETRY. THEOREM XVIII. 481 The area of a trapezoid is equal to half the product of its altitude by the sum of its parallel sides. Let EF be the altitude of the trapezoid AB CD; then the area of ABC D EC Draw the diagonal BD ; it... | |
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The area of a trapezoid is equal to one.half the product of its altitude and the sum of its bases. 
