 | Webster Wells - Geometry - 1899 - 196 pages
...angles of a spherical polygon of n sides is greater than 2 n — 4, and less than 2 n, right angles. 6. The arc of a great circle drawn from the vertex of an isosceles spherical triangle to the middle point of the base, is perpendicular to the base, and bisects the vertical angle. PROP. XXXI. THEOREM... | |
 | George Albert Wentworth - Geometry, Solid - 1902 - 246 pages
...mutually equilateral. .'. A ABD and ACD are mutually equiangular. § 810 .'.ZB = ZC. QED 813. COR. The arc of a great circle drawn from the vertex of...isosceles spherical triangle to the middle of the base bisects the vertical angle, is perpendicular to the base, and divides the triangle into two symmetrical... | |
 | George Albert Wentworth - Geometry - 1904 - 496 pages
...equilateral. .-.A ABD and ACD are mutually equiangular. § 810 • ' • £- B = £- CQED 813. COR. The arc of a great circle drawn from the vertex of...isosceles spherical triangle to the middle of the base bisects the vertical angle, is perpendicular to the base, and divides the triangle into two symmetrical... | |
 | Wilbur Fisk Nichols - 1905 - 208 pages
...AC, and bisects AC. 3. Using the same figure, prove that the line joining the vertex of an isosceles triangle to the middle of the base is perpendicular to the base, and bisects the angle at the vertex. Prove BD -L AC, and that BD bisects Z B. By conditions, what parts of the triangles... | |
 | William Chauvenet - 1905 - 336 pages
...isosceles spherical triangle the angles, opposite the equal sides are equal. 2. Theorem.— The arc drawn from the vertex of an isosceles spherical triangle to the middle point of the base is perpendicular to the base, and bisects the vertical angle. 3. Theorem.—Tf two... | |
 | Joseph Claudel - Mathematics - 1906 - 758 pages
...third side of the second. 659. In an isosceles triangle (Fig. 29), the line Am drawn from the vertex to the middle of the base is perpendicular to the base and bisects the angle at the vertex. Fig. 44 Fig. 45 660. The diagonals of a parallelogram bisect each other; conversely,... | |
 | Edward Rutledge Robbins - Geometry - 1907 - 428 pages
...(Explain.) .-. they are mutually equiangular and symmetrical (?) (766). ... ZB = ZC(?) (749). 769. COR. The arc of a great circle drawn from the vertex of an isosceles spherical triangle to the midpoint of the base bisects the vertex. angle and is perpendicular to the base. (See 749.) 770. THEOREM.... | |
 | George William Myers, Sarah Catherine Brooks - Arithmetic - 1907 - 432 pages
...hexagon is 36'. Find the area of the hexagon? 30. A straight line drawn from the vertex of an isosceles triangle to the middle of the , base is perpendicular to the\ base. Find the area of a regular pentagon whose sides are 24", if the radius of the circular drawn around... | |
 | George William Myers, Sarah Catherine Brooks - Arithmetic - 1907 - 436 pages
...hexagon is 36'. Find the area of the hexagon? 30. A straight line drawn from the vertex of an isosceles triangle to the middle of the , base is perpendicular to the\ "base. Find the area of a FIGURE 152 FIGURE 153 regular pentagon whose sides are 24", if the radius of the... | |
 | George Albert Wentworth, George Wentworth - Geometry - 1912 - 602 pages
...or 4. Therefore diameter of QAB = 2x4 in., or 8 in., by § 163. § 297 Ax. 9 Ax. 9 Ax. 9 Ax. 5 QEF 4 . The arc of a great circle drawn from the vertex of an isosceles spherical triangle to the mid-point of the base bisects the vertical angle, is perpendicular to the base, and divides the triangle... | |
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ADC ; the last two are therefore right angles ; hence the arc drawn from the vertex of an isosceles spherical triangle to the middle of the base, is perpendicular to the base, and bisects the vertical angle. PROPOSITION XVI. 
