| Popular educator - History - 1852
...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... | |
| Robert Simson - Trigonometry - 1775 - 520 pages
...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... | |
| Euclid - 1781 - 520 pages
...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... | |
| Euclid, Robert Simson - Geometry - 1781 - 466 pages
...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... | |
| Proclus (Diadochus.), Marinus (of Naples.) - 1788
...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... | |
| John Playfair - Euclid's Elements - 1795 - 400 pages
...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... | |
| Alexander Ingram - Trigonometry - 1799 - 351 pages
...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... | |
| Robert Simson - Trigonometry - 1804
...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... | |
| Euclides - Euclid's Elements - 1816 - 528 pages
...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... | |
| John Playfair - Circle-squaring - 1819 - 333 pages
...any triangle be produced, the exterior ang.Le is equal tojhe 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... | |
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