Books Books If a side of any triangle be produced, the exterior angle is equal to the two interior and opposite angles ; and the three interior angles of every triangle are equal to two right angles. The Elements of Euclid [book 1] for beginners, by J. Lowres - Page 29
by Euclides - 1852 ## The Popular Educator, Volumes 5-6; Volume 14

Geography - 1867 - 878 pages
...connected with our present subject. Euclid has proved, in the 32nd Proposition of his First BccV. that the three interior angles of every triangle are equal to two right angles, that is, to 180°. Let the hear this fact in mind. Hence it follows that if the of any two angles of... ## The Elements of Euclid, Viz: The Errors, by which Theon, Or Others, Have ...

Robert Simson - Trigonometry - 1775 - 520 pages
...IF a fide of any triangle be producedi the exterior angle is equal to the two interior and oppofite angles ; and the three interior angles of every triangle are equal to two right angles. Let ABC be a triangle, and let one of its fides BC be produced to D ; the exterior angle ACD is equal... ## The First Six Books: Together with the Eleventh and Twelfth

Euclid - 1781 - 550 pages
...TF a fide of any triangle be produced, the exterior angle is equal to the two interior and oppofite angles ; and the three interior angles of every triangle are equal to two right angles. Let ABC be a triangle, and let one of its fides BC be produced to D ; the exterior angle ACD is equal... ## The Elements of Euclid: The Errors, by which Theon, Or Others, Have Long Ago ...

Robert Simson - Trigonometry - 1781 - 466 pages
...TF a fide of any triangle be produced, the exterior angle is equal to the two interior and oppofite angles ; and the three interior angles of every triangle are equal to two right angles. Let ABC be a triangle, and let one of its fides BC be produced to D. the exterior angle ACD is equal... ## The philosophical and mathematical commentaries of Proclus ... on the first ...

Proclus (Diadochus.) - 1788 - 350 pages
...under fome general* klea, of which we pofleis a previous knowledge : thus, he who already knows that the three interior angles of) every triangle are equal to two right, and' is as yet ignorant that fome particular figure delineated on paper is- a triangle, isv no fooner... ## Elements of Geometry: Containing the First Six Books of Euclid, with Two ...

John Playfair - Trigonometry - 1795 - 444 pages
...a fide of any triangle be produced, the exterior J. angle is equal to the two interior and oppofite angles ; and the three interior angles of every triangle are equal to two right angles. Let ABC be a triangle, and let one of its fides BC be produced to D ; the exterior angle ACD is equal... ## The Elements of Euclid: Viz. the First Six Books, with the Eleventh and ...

Alexander Ingram - Trigonometry - 1799 - 351 pages
...IF a fide of any triangle be produced, the exterior angle is equal to the two interior and oppoiite angles ; and the three interior angles of every triangle are equal to two right angles. Let ABC be a triangle, and let one of its fides BC be produced to D ; the exterior angle ACD is equal... ## The Elements of Euclid: Also the Book of Euclid's Data ...cor. viz. The ...

Robert Simson - Trigonometry - 1804
...IF a fide of any triangle be produced, the exterior angle is equal to the two interior and oppofite angles ; and the three interior angles of every triangle are equal to two right angles. Let ABC be a triangle, and let one of its fides BC be produced to D. the exterior angle ACD is equal... ## Elements of Geometry: Containing the First Six Books of Euclid, with a ...

John Playfair - Euclid's Elements - 1806 - 320 pages
...THEOR; IF a side of any triangle be produced, the exterior /' angle is equal to the two interior and opposite angles ; and the three interior angles of every triangle are equal to two right angles. Let ABC be a triangle, and let one of its sides BC be produced to D ; the exterior angle ACD is equal... 