Ex 10.5, 12 - Prove that cyclic parallelogram is a rectangle - Ex 10.5

  1. Chapter 10 Class 9 Circles
  2. Serial order wise
Ask Download


Ex 10.5, 12 Prove that a cyclic parallelogram is a rectangle. Given: Let ABCD be a cyclic parallelogram To prove: ABCD is a rectangle Proof: A rectangle is a parallelogram with one angle 90° So, we have to prove angle 90° Since ABCD is a parallelogram ∠A = ∠C In cyclic parallelogram ABCD ∠A + ∠C = 180° ∠A + ∠A = 180° 2∠A = 180° ∠A = (180°)/2 = 90° So, ABCD is a parallelogram with one angle 90° Hence, ABCD is a rectangle

About the Author

Davneet Singh's photo - Teacher, Computer Engineer, Marketer
Davneet Singh
Davneet Singh is a graduate from Indian Institute of Technology, Kanpur. He has been teaching from the past 7 years. He provides courses for Mathematics and Science from Class 6 to 12. You can learn personally from here https://www.teachoo.com/premium/maths-and-science-classes/.