## Elements of Geometry and Trigonometry |

### From inside the book

Page 122

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**radius**by the constant number , which represents the circumference whose diameter is 1 , or the ratio of the circumference to the diameter . D M B In like manner , the area of the circle , whose**radius**is OB , will be equal to π × OВ2 ...Page 182

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**radius**of the circle inscribed in the polygon . B A F D E If the semicircle and semi - polygon be -evolved about EA ...**radius**. Ο Scholium 1. The solidity of every spherical sector is equal to the zone which forms its base , multiplied ...Page 238

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**radius**being equal to unity . THEOREM II . In every right angled triangle ,**radius**is to the tangent of either of the acute angles , as the side adjacent to the side opposite . Let CAB be the proposed triangle . With any**radius**, as CD ...### Contents

Ratios and Proportions | 34 |

The Circle and the Measurement of Angles | 41 |

Problems relating to the First and Third Books | 57 |

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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 logarithm M.
M. Sine 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 slant height solid angle solid described sphere spherical polygon spherical triangle square described straight line Tang tangent THEOREM triangle ABC triangular prism vertex