 In any obtuse triangle, the square of the side opposite the obtuse angle is equal to the sum of the squares of the other two sides, increased by twice the product of one of these sides and the projection of the other side upon it.  Elements of Geometry: Plane geometry - Page 148by Andrew Wheeler Phillips, Irving Fisher - 1896Full view - About this book
 | James Blaikie - 1892 - 74 pages
...[§384. Prove, by means of a geometrical construction, that in obtuse-angled triangles the square on the side opposite the obtuse angle is equal to the sum of the squares on the other two sides, together with twice the rectangle contained by either of these sides,... | |
 | George Albert Wentworth, George Anthony Hill - Geometry - 1894 - 150 pages
...the product of the whole secant and its external segment is equal to the square of the tangent. 7. In an obtuse-angled triangle the square of the side...opposite the obtuse angle is equal to the sum of the squares of the other two sides, increased by twice the product of one of these sides and the projection... | |
 | Webster Wells - Geometry - 1894 - 398 pages
...~2BCX CD. Whence, (§ 273.) PROPOSITION XXIX. THEOREM. 278. In any triangle having an obtuse angle, the square of the side opposite the obtuse angle is equal to the sum of the squares of the other two sides, plus twice the product of one of these sides and the projection of... | |
 | Charles Ambrose Van Velzer, George Clinton Shutts - Geometry - 1894 - 522 pages
...XIII. THKORKM. 279. The square on the side opposite an obtuse angle of a triangle equals the sum of the squares of the other two sides plus twice the product of one of the tides by the projection of the other side upon that side. K Let AB Cbea triangle, of which the... | |
 | Andrew Wheeler Phillips, Irving Fisher - Geometry - 1896 - 276 pages
...Substituting this value in (2), SUMMARY : ci = mi+yi=ai§317 §317 QED PROPOSITION XIX. THEOREM 326. In an obtuse-angled triangle the square of the side...opposite the obtuse angle is equal to the sum of the squares of the other two sides, plus twice the product of one of these sides and the projection of... | |
 | George D. Pettee - Geometry, Modern - 1896 - 272 pages
...(2) DC=BD— BC (Fig. 1) (Fig. 2) [squarin or (2). (1)1 aAAAff | ~I PROPOSITION XIII 264. Theorem. ln an obtuse-angled triangle the square of the side opposite the obtuse angle is equal to the sum, of the squares of the other two sides plus twice the product of one of these sides and the projection of tJie... | |
 | George Albert Wentworth - Mathematics - 1896 - 68 pages
...the product of one of those sides and the projection of the other upon that side. 343. In any obtuse triangle, the square of the side opposite the obtuse angle is equal to the sum of the squares of the other two sides increased by twice the product of one of those sides and the projection... | |
 | Andrew Wheeler Phillips, Irving Fisher - Geometry - 1896 - 570 pages
...ci = m'i+y'—a' _ zan + n' + y' = a' _ §317 QED PROPOSITION XIX. THEOREM 326. In an obtuse -angled triangle the square of the side opposite the obtuse angle is equal to the sum of the squares of the other two sides, plus twice the product of one of these sides and the projection of... | |
 | George Washington Hull - Geometry - 1897 - 408 pages
...between the projections of the extremno f~.f r>/~i •0F PROPOSITION IX. THEOREM. 238. In any obtuse triangle, the square of the side opposite the obtuse angle is equal to the sum of the squares of the other two sides, plus twice the product of one of these sides and the projection of... | |
 | Northwest Territories Council of Public Instruction - 1897 - 628 pages
...angles of a triangle meet in one point. 2. (a) Prove that in obtuse angled triangles, the square on the side opposite the obtuse angle is equal to the sum of the squares on the other two sides increased by twice the rectangle contained by either of those sides... | |
| |
