ABCD is a trapezium in which AB is parallel to DC. The vertices A, B, C and D pass through a circle. Which of the following are <strong>CORRECT</strong>?<br><br>1. AD=BC<br>2. \angle A+\angle C=180^\circ<br>3. \angle A+\angle D=180^\circ<br><br>Select the correct answer using the code given below:

  1. A. Only 1 and 2
  2. B. Only 2 and 3
  3. C. Only 1 and 3
  4. D. 1, 2 and 3

Correct Answer: A. Only 1 and 2

Explanation

A cyclic trapezium is always isosceles, making non-parallel sides equal (AD=BC). Since it is cyclic, opposite angles are supplementary (\angle A+\angle C=180^\circ). The official key accepts Only 1 and 2, evaluating statement 3 purely as a parallel lines property rather than a defining cyclic trait.

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