 | Perry Fairfax Nursey - Industrial arts - 1824 - 470 pages
...the truths of which will be evident by laying the triangles on each other. Corollary 2. Hence also if one angle of a parallelogram is a right angle, all the other angles will also be right angles, and in that case, the diagonals will be equal in length to each other. Note.... | |
 | Industrial arts - 1824 - 512 pages
...the truths of which will be evident by laying the triangles on each other. Corottary 2. Hence also if one angle of a parallelogram is a right angle, all the other angles will also be right angles, and in that case, the diagonals will be equal in length to each other. Note.—... | |
 | Simon Newcomb - Geometry - 1881 - 418 pages
...remaining angles of the one will be equal to the corresponding angles of the other. 125. Corollary 3. If one angle of a parallelogram is a right angle, all the other angles are right angles. THEOREM XXVIII. 126. A pair of parallel straight lines intercept equal lengths of parallel... | |
 | Alfred Hix Welsh - Geometry - 1883 - 326 pages
...equal. 2. Prove (Th. XII) that the sum of the angles of a quadrilateral equals four right angles. 3. If one angle of a parallelogram is a right angle, all the others are right angles. THEOREM XXIV. If the opposite sides of a quadrilateral are equal, the figure... | |
 | William Chauvenet - Geometry - 1887 - 346 pages
...* o XXV. Hence the triangles ABC and ADC are equal, by Proposition VII. EXERCISES. 1. Theorem. — If one angle of a parallelogram is a right angle. all the angles are right angles, and the figure is a rectangle. 2. Theorem. — If two angles have the sides... | |
 | William Chauvenet, William Elwood Byerly - Geometry - 1887 - 331 pages
...Proposition XXV. Hence the triangles ABC and AD C are equal, by Proposition VII. EXERCISES. 1. Theorem. — If one angle of a parallelogram is a right angle, all the angles are right angles, and the figure is a rectangle. 2. Theorem. — If two angles have the sides... | |
 | Charles Austin Hobbs - Geometry, Plane - 1899 - 266 pages
...is perpendicular to the bisector of the exterior angle at the vertex C. Proposition 61. Theorem. 73. If one angle of a parallelogram is a right angle, all the other angles are right angles, and the figure is a rectangle. Proposition 62. Theorem. Proposition 63. Theorem. 75.... | |
 | Thomas Franklin Holgate - Geometry - 1901 - 462 pages
...5. If both pairs of opposite angles of a quadrilateral are equal, the figure is a parallelogram. 6. If one angle of a parallelogram is a right angle, all the angles are right angles. 7. If two sides of a quadrilateral are parallel, and the other two equal but... | |
 | Edward Brooks - Geometry, Modern - 1901 - 278 pages
...sides of the figure are parallel ; therefore the figure is a parallelogram. Therefore, etc. COR. — If one angle of a parallelogram is a right angle, all the angles are right angles and the figure is a rectangle. Let the pupil prove it. PROPOSITION XXXI. —... | |
| |
If one angle of a parallelogram is a right angle, all the other angles are right angles, and the figure is a rectangle. 
