### Contents

 PLANE GEOMETRY 3 Book I 12 Book V 18 LINES AND PLANES IN SPACE DIEDRAL 175 BOOK VII 209
 THE CYLINDER AND CONE 240 THE SPHERE 256 PAGE 297 Copyright

### Popular passages

Page 166 - S' denote the areas of two � whose radii are R and R', and diameters D and D', respectively. Then, | = "* � = �� = �• <�337> That is, the areas of two circles are to each other as the squares of their radii, or as the squares of their diameters.
Page 17 - In an isosceles triangle the angles opposite the equal sides are equal.
Page 136 - ... 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 166 - Similar arcs are to each other as their radii; and similar sectors are to each other as the squares of their radii.
Page 50 - If the diagonals of a quadrilateral bisect each other, the figure is a parallelogram.
Page 126 - In any triangle, the product of any two sides is equal to the product of the segments of the third side formed by the bisector of the opposite angle, plus the square of the bisector.
Page 263 - A spherical polygon is a portion of the surface of a sphere bounded by three or more arcs of great circles. The...
Page 280 - A zone is a portion of the surface of a sphere included between two parallel planes.
Page 239 - Every section of a cylinder made by a plane passing through an element is a parallelogram. Given ABCD, a section of cylinder AC, made by plane through element AB.
Page 254 - A sphere is a solid bounded by a surface all points of which are equally distant from a point within called the centre.