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In Δs ABC and DEF, AB||DE; BC=EF and BC||EF. Vertices A, B and C are joinedto vertices D, E and F respectively (see figure). Show that(i) ABED is a parallelogram(ii) BCFE is a parallelogram(iii) AC=DF(iv) ΔABC≅ΔDEF |
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Answer» Hey there! -------- (i) ABED is a PARALLELOGRAM. Given : △ABC and △DEF, AB = DE, AB II DE, BC = EF and BC = EF To Prove : ABED is a parallelogram. Proof : Given that AB = DE and AB II DE => [One pair of opposite sides is PARALLEL and equal.] Hence, ABED is a parallelogram. (ii) BCFE is a parallelogram. Proof : Given that BC = EF and BC II EF => [One pair of opposites sides is parallel and equal.] Hence, BCFE is a parallelogram. (iii) AC = DF Proof :
From (i) and (ii) we get, AD = CF and AD II CF => [One pair of opposite sides are equal and parallel to each other.] Therefore, ACFD is a parallelogram. So, AC = DF ...........[Opposite sides of parallelogram] (IV) △ABC ≅ △DEF Proof : AB = DE ........(given) BC = EF ........(given) AC = DF .......[proved in (iii)} Hence, △ABC ≅ △DEF ..............[By SSS congruence rule] |
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