 | George Albert Wentworth - Geometry - 1904 - 496 pages
...a right triangle the two acute angles are together equal to one right angle, or 90°. 136. COR. 7. In an equiangular triangle, each angle is one third of two right angles, or 60°. 137. COR. 8. An exterior angle of a triangle is equal to the sum of the two opposite interior... | |
 | Francis Fisher Browne - American literature - 1906 - 894 pages
...charcoal diagram on the floor of his play-room, the thirty-second proposition of the first book of Euclid (the exterior angle of a triangle is equal to the sum of the two interior and opposite angles, and the three angles of a triangle together equal two right angles).... | |
 | Royal Geographical Society (Great Britain) - Scientific expeditions - 1906 - 514 pages
...rays = Z_ BE 6 ; and .'. Z ab B = 2 Z pb B, and Z&BE = 2Z&BP, FIG. But and - Z &B P = Z &PB because the exterior angle of a triangle is equal to the sum of the interior and opposite angles; instrument, is divided into 10' or 20', and those are subdivided... | |
 | Ernst Rudolph Breslich - Mathematics - 1909 - 402 pages
...8. // two angles have their sides parallel respectively they are either equal or supplementary. 9. The exterior angle of a triangle is equal to the sum of the two remote interior angles. 11. The consecutive angles of a parallelogram arc supplementary. 217.... | |
 | Education - 1904 - 484 pages
...ABC. Give reasons. If a few more exercises of this type are given the children should observe that the exterior angle of a triangle is equal to the sum of the two remote interior angles. 2. Draw a scalene triangle ABD, then draw the line A C. Suppose that... | |
 | Edith Long, William Charles Brenke - Geometry, Modern - 1916 - 292 pages
...straight angle. Z BAC + Z ACB + Z CBA = a straight angle. Why? State the theorem proved. Corollary 1. The exterior angle of a triangle is equal to the sum of the interior angles not adjacent to it. Corollary 3. // two angles of a triangle are equal respectively... | |
 | Edith Long, William Charles Brenke - Geometry, Plane - 1916 - 292 pages
...or supplemental. Theorem XX. The sum of the angles of a triangle is a straight angle. Corollary 1. The exterior angle of a triangle is equal to the sum of the interior angles not adjacent to It. Corollary 2. A triangle can have but one right angle or one... | |
 | Mabel Sykes, Clarence Elmer Comstock - Geometry, Modern - 1918 - 576 pages
...are equal. COR. III. The acute angles of a right triangle are complements of each other. THEOREM lit. The exterior angle of a triangle is equal to the sum of the two non-adjacent interior angles. THEOREM 20. The sum of the interior angles of a polygon of n... | |
 | Raleigh Schorling, William David Reeve - Mathematics - 1922 - 460 pages
...5. 6. Or 7. But Z x is measured by BC. 1. One and only one line can be drawn between two points. 2. The exterior angle of a triangle is equal to the sum of the two remote interior angles. 3. Radii of the same circle are equal. 4. Base angles of an isosceles... | |
 | Mabel Sykes, Clarence Elmer Comstock - Geometry, Solid - 1922 - 236 pages
...are equal. COR. III. The acute angles of a right triangle are complements of each other. THEOREM 19. The exterior angle of a triangle is equal to the sum of the two non-adjacent interior angles.^ ^ THEOREM 20. The sum of the interior angles of a polygon of... | |
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The exterior angle of a triangle is equal to the sum of the two opposite interior angles. 
