Theorem 8.2 - Chapter 8 Class 9 Quadrilaterals

Last updated at August 5, 2026 by

Theorem 8.2 - Class 9 - In parallelogram, opposite sides are equal - Theorems

 

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Theorem 8.2: In a parallelogram, opposite sides are equal. Given: A parallelogram ABCD with AC as its diagonal To prove: ΔABC ≅ ΔADC Proof: Opposite sides of parallelogram is parallel So, AB ∥ DC and AD‖∥ BC In Δ ABC & Δ ADC ∠ BAC = ∠ DCA AC = AC ∠ DAC = ∠ BCA ∴ ΔABC ≅ ΔADC Hence, AB = CD & AD = BC Hence proved

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