# Elements of Plane and Solid Geometry

Ginn and Heath, 1877 - Geometry - 398 pages

### Contents

 RECTILINEAR FIGURES 3 SUPERPOSITION 11 PARALLEL LINES 25 TRIANGLES 37 QUADRILATERALS 58 POLYGONS IN GENERAL 68
 COMPARISON AND MEASUREMENT OF THE SUR 174 REGULAR POLYGONS AND CIRCLES 210 PLANES AND SOLID ANGLES 251 POLYHEDRONS CYLINDERS AND CONES 286 THE SPHERE 349 Copyright

### Popular passages

Page 126 - To describe an isosceles triangle having each of the angles at the base double of the third angle.
Page 179 - ... any two parallelograms are to each other as the products of their bases by their altitudes. PROPOSITION V. THEOREM. 403. The area of a triangle is equal to half the product of its base by its altitude.
Page 46 - In an isosceles triangle the angles opposite the equal sides are equal.
Page 83 - A straight line perpendicular to a radius at its extremity is a tangent to the circle. Let MB be perpendicular to the radius OA at A.
Page 349 - A sphere is a solid bounded by a surface all points of which are equally distant from a point within called the centre.
Page 146 - The areas of two triangles which have an angle of the one equal to an angle of the other are to each other as the products of the sides including the equal angles. A D A' Hyp. In triangles ABC and A'B'C', To prove AABC A A'B'C' A'B' x A'C ' Proof. Draw the altitudes BD and B'D'.
Page 186 - 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 diminished by twice the product of one of those sides and the projection of the other upon that side.
Page 207 - To construct a parallelogram equivalent to a given square, and having the difference of its base and altitude equal to a given line.
Page 134 - In a series of equal ratios, the sum of the antecedents is to the sum of the consequents as any antecedent is to its consequent.
Page 179 - Two right triangles are congruent if the hypotenuse and a side of the one are equal respectively to the hypotenuse and a side of the other. c c...