InterviewSolution
Saved Bookmarks
| 1. |
If A, B, C, D are the successive angles of a cyclic quadrilateral, then what is cos A + cos B + cos C + cos D equal to:(a) 4 (b) 2 (c) 1 (d) 0 |
|
Answer» (d) 0 In a cyclic quadrilateral, the sum of the opposite angles is 180°. ⇒ A + C = 180° and B + D = 180° ∴ cos A + cos B + cos C + cos D = cos A + cos B + cos (180° – C) + cos (180° – B) = cos A + cos B – cos A – cos B = 0. |
|