The elements of plane geometry; or, The first six books of Euclid, ed. by W. Davis1863 |
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Αποτελέσματα 6 - 10 από τα 45.
Σελίδα 19
... AC is equal ( I. 4 ) to the base DF , and the third angle BAC to the third angle EDF . Therefore , if two triangles , & c . Q. E. D. PROP . XXVII . ( THEOREM . ) - If a straight line ( EF ) falling on two other straight lines ( A B , CD ) ...
... AC is equal ( I. 4 ) to the base DF , and the third angle BAC to the third angle EDF . Therefore , if two triangles , & c . Q. E. D. PROP . XXVII . ( THEOREM . ) - If a straight line ( EF ) falling on two other straight lines ( A B , CD ) ...
Σελίδα 21
Euclides William Davis (B.A.). A in the straight line AD , make ( I. 23 ) the angle DAE equal to the angle ADC ... AC meets them , the angle ACE is equal ( I. 29 ) to the alternate angle BAC . Again , because CE is parallel to AB ...
Euclides William Davis (B.A.). A in the straight line AD , make ( I. 23 ) the angle DAE equal to the angle ADC ... AC meets them , the angle ACE is equal ( I. 29 ) to the alternate angle BAC . Again , because CE is parallel to AB ...
Σελίδα 22
... right angles . Take from these equals all the interior angles . Therefore all the exterior angles of the figure are equal ( Ax . 3 ) to four right angles D. B PROP . XXXIII . ( THEOREM . ) - The straight lines ( AC , BD ) which join the ...
... right angles . Take from these equals all the interior angles . Therefore all the exterior angles of the figure are equal ( Ax . 3 ) to four right angles D. B PROP . XXXIII . ( THEOREM . ) - The straight lines ( AC , BD ) which join the ...
Σελίδα 25
... straight line but AD is parallel to BC . Therefore AD is parallel to BC . Wherefore , equal triangles upon , & c ... AC . The triangle ABC is equal to the triangle EBC с ( I. 37 ) , because they are upon the BOOK I. - PROP . XL . 25.
... straight line but AD is parallel to BC . Therefore AD is parallel to BC . Wherefore , equal triangles upon , & c ... AC . The triangle ABC is equal to the triangle EBC с ( I. 37 ) , because they are upon the BOOK I. - PROP . XL . 25.
Σελίδα 26
... AC bisects it . Therefore the parallelogram BD is also double of the triangle EBC . Therefore , if a parallelo- gram and a triangle , & c . Q. E. D. A DE PROP . XLII . ( PROBLEM ... straight line with AB . 26 EUCLID'S ELEMENTS .
... AC bisects it . Therefore the parallelogram BD is also double of the triangle EBC . Therefore , if a parallelo- gram and a triangle , & c . Q. E. D. A DE PROP . XLII . ( PROBLEM ... straight line with AB . 26 EUCLID'S ELEMENTS .
Συχνά εμφανιζόμενοι όροι και φράσεις
ABC is equal ABCD adjacent angles alternate angle angle ABC angle ACB angle BAC angle BCD angle DEF angle EDF arc BC base BC bisected centre circle ABC circumference double equal angles equal Ax equal Const equal Hyp equal to F equals add equiangular equimultiples exterior angle four magnitudes fourth G and H given straight line gnomon greater ratio greater than F interior and opposite join less multiple opposite angle parallel parallelogram parallelogram BD perpendicular PROBLEM.)-To produced Q. E. D. PROP rectangle contained remaining angle right angles segment side BC square of AC straight line AB straight line AC THEOREM.)-If three straight lines touches the circle triangle ABC triangle DEF twice the rectangle whole angle
Δημοφιλή αποσπάσματα
Σελίδα 3 - A plane superficies is that in which any two points being taken, the straight line between them lies wholly in that superficies. VIII. A plane angle is the inclination of two lines to one another in a plane, which meet together, but are not in the same direction.
Σελίδα 4 - A circle is a plane figure contained by one line, which is called the circumference, and is such that all straight lines drawn from a certain point within the figure to the circumference, are equal to one another : XVI.
Σελίδα 67 - The first of four magnitudes is said to have the same ratio to the second, which the third has to the fourth, when any equimultiples whatsoever of the first and third being taken, and any equimultiples whatsoever of the second and fourth ; if the multiple of the first be less than that of the second, the multiple of the third is also less than that of the fourth...
Σελίδα 12 - When a straight line standing on another straight line makes the adjacent angles equal to one another, each of the angles is called a right angle ; and the straight line which stands on the other is called a perpendicular to it.
Σελίδα 93 - From this it is manifest, that the perpendicular drawn from the right angle of a right-angled triangle to the base, is a mean proportional between the segments of the base; and also that each of the sides is a mean proportional between the base, and...
Σελίδα 68 - This word is used when there are four proportionals, and it is inferred that the first has the same ratio to the third which the second has to the fourth ; or that the first is to the third as the second to the fourth : as is shown in Prop.
Σελίδα 5 - LET it be granted that a straight line may be drawn from any one point to any other point.
Σελίδα 88 - From this it is plain, that triangles and parallelograms that have equal altitudes, are to one another as their bases. Let the figures be placed so as to have their bases in the same straight line; and having drawn perpendiculars from the vertices of the triangles to the bases, the straight line which joins the vertices is parallel to that in which their bases are, (I.
Σελίδα 69 - This term is used when the first magnitude is to the second of the first rank, as the last but one is to the last of the second rank; and as the second is to the third of the first rank, so is the last but two to the last but one of the second rank; and as the third is to the fourth of the first rank, so is the third from the last to the last but two of the second rank; and so on in a cross order: and the inference is as in the 18th definition.
Σελίδα 21 - ... figure, together with four right angles, are equal to twice as many right angles as the figure has be divided into as many triangles as the figure has sides, by drawing straight lines from a point F within the figure to each of its angles.