# Elements of Geometry and Trigonometry from the Works of A.M. Legendre: Adapted to the Course of Mathematical Instruction in the United States

A.S. Barnes, 1872 - 455 СЕКъДЕР

### тИ КщМЕ ОИ ВЯчСТЕР -сЩМТАНГ ЙЯИТИЙчР

дЕМ ЕМТОПъСАЛЕ ЙЯИТИЙщР СТИР СУМчХЕИР ТОПОХЕСъЕР.

### дГЛОЖИКч АПОСПэСЛАТА

сЕКъДА 99 - The area of a parallelogram is equal to the product of its base and altitude.
сЕКъДА 90 - PROBLEM XV. To inscribe a circle in a given triangle. Let ABC be the given triangle. Bisect the angles A and B, by the lines AO and BO, meeting in the point 0 (Prob.
сЕКъДА 46 - All the interior angles of any rectilineal figure, together with four right angles, are equal to twice as many right angles as the figure has sides.
сЕКъДА 43 - In any triangle, the sum of the two sides containing either angle, is to their difference, as the tangent of half the sum of the two other angles, to the tangent of half their difference.
сЕКъДА 104 - The square described on the hypothenuse of a rightangled triangle is equal to the sum of the squares described on the other two sides.
сЕКъДА 31 - THEOREM. If two angles of a triangle are equal, the sides opposite to them are also equal, and consequently, the triangle is isosceles.
сЕКъДА 16 - A SCALENE TRIANGLE is one which has no two of its sides equal ; as the triangle GH I.
сЕКъДА 28 - If two triangles have two sides of the one equal to two sides of the other, each to each, and the included angles unequal, the third sides will be unequal; and the greater side will belong to the triangle which has the greater included angle.
сЕКъДА 6 - The logarithm of any power of a number is equal to the logarithm of the number multiplied by the exponent of the power.
сЕКъДА 154 - DE, are like parts of the circumferences to which they belong, and similar sectors, as A CH and 'D OE, are like parts of the circles to which they belong : hence, similar arcs are to each other as their radii, and similar sectors are to each other as the squares of their radii.