Check sibling questions

Theorem 8.4 - Class 9 - In parallelogram, opposite angles are equal.jpg

Theorem 8.4 - Chapter 8 Class 9 Quadrilaterals - Part 2

This video is only available for Teachoo black users


Theorem 8.4: In a parallelogram, opposite angles are equal Given: A parallelogram ABCD with AC as its diagonal To prove: ∠ A = ∠ C & ∠ B = ∠ D Proof: Opposite sides of parallelogram is parallel So, AB ∥ DC and AD‖∥ BC Adding (1) and (2) ∠BAC + ∠DAC = ∠DCA + ∠ BCA ∠BAD = ∠DCB Similarly, we can prove ∠ADC = ∠ABC Hence Proved.

Davneet Singh's photo - Teacher, Engineer, Marketer

Made by

Davneet Singh

Davneet Singh is a graduate from Indian Institute of Technology, Kanpur. He has been teaching from the past 12 years. He provides courses for Maths and Science at Teachoo.