## Elements of Geometry and Trigonometry |

### From inside the book

Page 118

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**regular**, they will be similar ( Prop . I. ) ; and therefore when they become equal , they will exactly coin- cide ...**regular**polygon is equal to its perimeter , multi- plied by half the radius of the inscribed circle . Let there be the ...Page 182

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**regular**poly- gon , as the isosceles triangle OAB , is measured by πOI2 × AF ( Prop . XII . Cor . ) ; and when the polygon becomes the circle , the portion OAB becomes the sector AOB , OI becomes equal to OA , and the solid described ...Page 296

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**regular**polyedrons , when the edges are equal to 1 . A TABLE OF THE**REGULAR**POLYEDRONS WHOSE EDGES ARE 1 . . . . . . . . Names . Tetraedron Hexacdron Octaedron . Dodecaedron Icosaedron No. of Faces . 4 6 8 12 20 Surface . 1.7320508 ...### Contents

BOOK | 7 |

Problems relating to the First and Third Books 57 | 57 |

BOOK IV | 68 |

14 other sections not shown

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### Common terms and phrases

adjacent adjacent angles altitude angle ACB angle BAC ar.-comp base multiplied bisect Book VII centre chord circ circumference circumscribed common cone consequently convex surface cosine Cotang cylinder diagonal diameter dicular distance divided draw drawn equally distant equations equivalent feet figure find the area formed four right angles frustum given angle given line gles greater homologous sides hypothenuse inscribed circle inscribed polygon intersection less Let ABC number of sides opposite parallelogram parallelopipedon pendicular perimeter perpen perpendicular plane MN polyedron polygon ABCDE PROBLEM Prop proportional PROPOSITION pyramid quadrant quadrilateral quantities radii radius ratio rectangle regular polygon right angled triangle S-ABC Scholium secant segment similar sine slant height solid angle solid described sphere spherical polygon spherical triangle square described straight line TABLE OF LOGARITHMIC tang tangent THEOREM triangle ABC triangular prism vertex