| Bernard Marks - Geometry - 1871 - 172 pages
...FIRST LESSONS IN GEOMETRY. PROPOSITION XVIII. THEOREM. DEMONSTRATION. We wish to prove, that, In any isosceles triangle, the angles opposite the equal sides are equal. Let the triangle AB c be isosceles, having the side AB equal to the side A c ; then will the angle B, opposite... | |
| Edward Olney - Geometry - 1872 - 472 pages
...the chords are equal, the arcs are, and hence the angles subtended by these arcs. 227. COR. 3. — In an isosceles triangle the angles opposite the equal sides are equal ; and, conversely, if two angles of a triangle are equal, the sides opposite are equal, and the triangle... | |
| Edward Olney - Geometry - 1872 - 562 pages
...the chords are equal, the arcs are, and hence the angles subtended by these arcs. 227. COR. 3. — In an isosceles triangle the angles opposite the equal sides are equal; and, conversely, if two angles of a triangle are equal, the sides opposite are equal, and the triangle... | |
| William Frothingham Bradbury - Geometry - 1872 - 262 pages
...intersection E. Therefore the two triangles coincide, and are equal in all respects. THEOREM X. 42. In an isosceles triangle the angles opposite the equal sides are equal. In the isosceles triangle ABC let AB and BC be the equal sides ; then the angle A is equal to' the... | |
| Benjamin Greenleaf - Geometry - 1873 - 202 pages
...side BA equal to ED, the side CA equal to FD, and the angle A equal to the angle D. THEOREM VI. 46. In an isosceles triangle, the angles opposite the equal sides are equal. Let ABC be an isosceles triangle, in which the side AB is equal to the side AC; then will the angle B be... | |
| William Frothingham Bradbury - Geometry - 1873 - 132 pages
...intersection E. Therefore the two triangles coincide, and are equal in all respects. THEOREM X. 42. In an isosceles triangle the angles opposite the equal sides are equal. In the isosceles triangle ABC let AB and BC be the equal sides ; then the angle A is equal to the angle... | |
| Adrien Marie Legendre - Geometry - 1874 - 500 pages
...triangles, equal in all their parts, the equal sides lie opposite the equal angles; and conversely. PROPOSITION XI. THEOREM. In an isosceles triangle the angles opposite the equal sides are equal. Let BAC be an isosceles triangle, having the side AB equal to the side AC: then will the angle C be equal... | |
| Benjamin Greenleaf - Geometry - 1874 - 206 pages
...side BA equal to ED, the side CA equal to FD, and the angle A equal to the angle D, THEOREM VI. 46. In an isosceles triangle, the angles opposite the equal sides are equal. Let ABC be an isosceles triangle, in which the side AB is equal to the side AC; then will the angle B be... | |
| United States Naval Academy - 1874 - 888 pages
...all the angles of a polygon of n sides. If the polygon is regular, what is each angle Î Prove that in an isosceles triangle the angles opposite the equal sides are equal. 2. Prove that the straight Hues which bisect two adjacent supplementary angles are perpendicular to... | |
| William Guy Peck - Conic sections - 1876 - 412 pages
...hence, the triangles are equal in all their parts, ( P. 8 ), which was to be proved. .PROPOSITION XII. THEOREM. In an isosceles triangle the angles opposite the equal sides are equal. Let ACD be an isosceles triangle in which CD is equal to DA. Let the base AC be bisected in E and from... | |
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