 In any triangle, the square of the side opposite an acute angle is equal to the sum of the squares of the other two sides, minus twice the product of one of these sides and the projection of the other side upon it.  Plane Geometry: With Problems and Applications - Page 205by Herbert Ellsworth Slaught, Nels Johann Lennes - 1918 - 310 pagesFull view - About this book
 | Alfred Challice Johnson - Plane trigonometry - 1865 - 166 pages
...(A) Which proves Rule II. PROPOSITION II. The square of any side of a triangle is equal to the sum of the squares of the other two sides, minus twice the product of those two sides, and the cosine of the angle included by them. First, let the triangle А В С be... | |
 | William Chauvenet - Geometry - 1871 - 380 pages
...opposite to an acute angle is equal to the sum of the squares of the other two sides diminished by twice the product of one of these sides and the projection of the other upon that side. Let (7 be an acute angle of the triangle ABC, A Pthe projection of A upon BC by the perpendicular... | |
 | Alfred Challice Johnson - Spherical trigonometry - 1871 - 178 pages
...(А) Which proves Rule II. PROPOSITION II. The square of any side of a triangle is equal to the sum of the squares of the other two sides, minus twice the product of those two sides, and the cosine of the anale included by them. First, let the triangle А В С be... | |
 | André Darré - 1872 - 226 pages
...H THEOREM. 91. In any triangle the square of a side opposite an acute angle is equal to the sum of the squares of the other two sides, minus twice the product of one of these sides by the projection on it of the other. Def. The projection of one line on another is the part of the... | |
 | William Chauvenet - Mathematics - 1872 - 382 pages
...opposite to an acute angle is equal to the sum of the squares of the other two sides diminished by twice the product of one of these sides and the projection of the other •upon that side. Let C be an acute angle of the triangle ABC, P the projection of A upon BC by the perpendicular... | |
 | William Chauvenet - Geometry - 1872 - 382 pages
...opposite to the obtuse angle is equal to the sum of the squares of the other two sides, increased by tunce the product of one of these sides and the projection of the other upon that side. Let C be the obtuse angle of the triangle ABC, -j^ P the projection of A upon BC (produced);... | |
 | Harvard University - 1874 - 668 pages
...opposite to an acute angle is equal to the Bum of the squares of the other two sides diminished by twice the product of one of these sides and the projection of the other upon that side. 7. The area of a trapezoid is equal to the product of its altitude by half the sum of its... | |
 | Henry Nathan Wheeler - Trigonometry - 1876 - 204 pages
...of half their difference . . 78 § 73. The square of any side of a triangle is equal to the sum of the squares of the other two sides, minus twice the product of those sides into the cosine of their included angle 73 § 74. Formula for the side of a triangle, in... | |
 | Henry Nathan Wheeler - 1876 - 128 pages
...— C)' 6 — c tani(B — C)' § 73. The square 'of any side of a triangle is equal to the sum of the squares of the other two sides, minus twice the product of those sides into the cosine of their included angle. FIG. 43. FIG 44. Through c in the triangle ABC... | |
 | William Frothingham Bradbury - Geometry - 1877 - 262 pages
...XXVIII. 68 1 In a triangle the square of a side opposite an acute angle is equivalent to the sum of the squares of the other two sides minus twice the product of one of these sides and the distance from the vertex of this acute angle to the foot of the perpendicular let fall upon this side... | |
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