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Class 9 - CirclesCircles, Class 9 math tutorials, cyclic quadrilateral, math, mathemafia, mathematics, NCERT, parallelogram, rectangle
Question 12: Prove that a cyclic parallelogram is a rectangle.
Prerequisite
It is commonly said that in mathematics one question can be solved in multiple ways. This question is another good example to prove it. This question has been solved by three different methods by using the following concepts.
- Opposite angles of a parallelogram are always congruent
- Same side interior angles on two parallel lines are supplementary
- Using congruence postulate
Theorem 8.4: In a parallelogram, opposite angles are equal.
Theorem 6.4: If a transversal intersects two parallel lines, then each pair of interior angles on the same side of the transversal is supplementary.
Congruence vs. Similarity
Chapter 10 – Circles