Given :
l || m and p || q
In Δ ABC and Δ CDA,
⇒ ∠BAC = ∠DCA (Alternate interior angles are equal)
⇒ AC = CA (Common side)
⇒ ∠BCA = ∠DAC (Alternate interior angles are equal)
∴ Δ ABC ≅ Δ CDA (By A.S.A. congruence rule)
Hence, proved that Δ ABC ≅ Δ CDA.
