 | Alan Sanders - Geometry - 1903 - 392 pages
...of the other pair of vertical angles. Find the values of the four angles. PROPOSITION X. THEOREM 81. In an isosceles triangle, the angles opposite the equal sides are equal. Let ABC be an isosceles A, having AB = BC. To Prove ZA = /L C. Proof. Draw BD bisecting AC. (§ 55.)... | |
 | Fletcher Durell - Geometry, Solid - 1904 - 232 pages
...hypotenuse and an acute angle of one are equal to the hypotenuse and. an acute angle of the other. 99. In an isosceles triangle the angles opposite the equal sides are equal. 100. // two angles of a triangle are equal, the sides opposite are equal, and the triangle is isosceles.... | |
 | Fletcher Durell - Geometry - 1911 - 553 pages
...=& DEF, Art. 47. (geometric figures which coincide are equal), Qc 1. B. PROPOSITION IX. THEOREM 99. In an isosceles triangle the angles opposite the equal sides are equal, B Given the isosceles A ABC in which AB = BC. To prove ZA - Z C. Proof e Let BD be drawn so as to bisect... | |
 | George Albert Wentworth - Geometry - 1904 - 496 pages
...always true, just as the converse of a theorem is not always true. PROPOSITION XXII. THEOREM. 145. In an isosceles triangle the angles opposite the equal sides are equal. B Z> C Let ABC be an isosceles triangle, having AB and AC equal. To prove that ZB = Z C. Proof. Suppose... | |
 | Fletcher Durell - Geometry, Plane - 1904 - 382 pages
...ABC= A DEF, (geometric figures which coincide are equal) . Art. 47. Q, ED 'PROPOSITION IX. THEOREM 99. In an isosceles triangle the angles opposite the equal sides are equal. B Given the isosceles A ABC in which AB=BC. To prove ZA = /. C. Proof. Let BD be drawn so as to bisect... | |
 | Cora Lenore Williams - Geometry - 1905 - 122 pages
...of a triangle to the middle point of the opposite side is called the median to that side. Prop. 3. In an isosceles triangle, the angles opposite the equal sides are equal. Prop. 4. An equilateral triangle is also equiangular. Prop. 5. If two angles of a triangle are equal,... | |
 | William Chauvenet - 1905 - 336 pages
...the one are respectively equal to a side and the two adjacent angles of the other. PROPOSITION VIII. In an isosceles triangle the angles opposite the equal sides are equal. Corollary. The straight line bisecting the vertical angle of an isosceles triangle bisects the base,... | |
 | Isaac Newton Failor - Geometry - 1906 - 431 pages
...opposite sides of the base. 56 HK and MN bisect each other at P. Prove PROPOSITION XIX. THEOREM 173 In an isosceles triangle, the angles opposite the equal sides are equal. HYPOTHESIS. ABC is an isosceles triangle, having AB = AC. CONCLUSION. ZB = Z C. PROOF Draw AD bisecting... | |
 | International Correspondence Schools - Building - 1906 - 634 pages
...equal to the angle C" AD, or to C' A1 B1, and by Art. 74 the triangles CA B and C' A' B' are equal. 76. In an isosceles triangle, the angles opposite the equal sides are equal. Let ABC, Fig. 51, be an isosceles triangle in which AB -B C. Draw the bisector BD of the angle B. Then,... | |
 | David Sands Wright - Geometry - 1906 - 104 pages
...interior angles on the same side of the transversal meet at an angle of ninety degrees. 6. Theorem. In an isosceles triangle, the angles opposite the equal sides are equal. 1. The vertical angle of an isosceles triangle is 12°, how many degrees in each of the angles at the... | |
| |
In an isosceles triangle the angles opposite the equal sides are equal. 
