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?

- 0
- 1
- 2
- 4

In cyclic quadrilateral, sum of opposite angles is 180°. You can assume all angles to be 90°.

cos 90° = 0

**The correct option is A.**

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