## Elements of Geometry and Trigonometry |

### From inside the book

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**likewise**be a right angle . Hence , the angle FCD is equal to the angle FCE ( Ax . 10. ) ; which can only be the case when the lines CD and CE coincide : there- fore , the straight lines which have two points A and B com- mon , cannot ... Page 20

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**likewise**equiangular , that is to say , has all its angles equal . Scholium . The equality of the triangles BAD , DAC , proves also that the angle BAD , is equal to DAC , and BDA to ADC , hence the latter two are right angles ... Page 22

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**likewise**be a right angle . But if the adja- cent angles BCA , BCF , are together equal to two right angles , ACF must be a straight line ( Prop . III . ) : from whence it fol- lows , that between the same two points , A and F , two ... Page 24

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**likewise**, are the two oblique lines AE , EB , the A two AF , FB , and so on . Therefore every point in the perpendicular is equally distant from the extremities A and B. E B Secondly , Let I be a point out of the perpen- dicular . If ... Page 25

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**likewise**equal to two right angles ( Prop . I. ) ; and taking away BAC from both , there will remain the angle ABD = BAE . Again , the angles EGA , BGF , are equal ( Prop . IV . ) ; there- fore , the triangles EGA and BGF , have each a ...### Other editions - View all

### Common terms and phrases

adjacent adjacent angles altitude angle ACB angle BAC ar.-comp base multiplied bisect Book centre chord circ circumference circumscribed common cone convex surface Cosine Cotang cylinder diagonal diameter dicular distance draw drawn equal angles equally distant equiangular equivalent figure formed four right angles frustum given angle given line gles greater homologous sides hypothenuse inscribed polygon intersection less Let ABC let fall logarithm measured by half number of sides oblique lines opposite parallelogram parallelopipedon pendicular perimeter perpen perpendicular plane MN polyedron polygon ABCDE prism proportional PROPOSITION pyramid quadrant quadrilateral quantities radii radius ratio rectangle regular polygon right angled triangle S-ABC Scholium secant secant line segment side BC similar sine solid angle solid described sphere spherical polygon spherical triangle square described straight line tang tangent THEOREM triangle ABC triangular prism vertex