if a diagonals of parallelogram are equal then show it is a rectangle
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if a diagonals of parallelogram are equal then show it is a rectangle
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Answer:
□ ABCD is a parallelogram
consider Δ ACD and Δ ABD
AC = BD …. (given)
AB = DC …. (opposite sides of parallelogram)
AD = AD …. (common side)
∴Δ ACD ≅Δ ABD (sss test of congruence)
∠ BAD = ∠ CDA …. (cpct)
∠BAD+∠CDA=180
∘
. [Adjacent angles of parallelogram are supplementary]
so ∠ BAD and ∠ CDA are right angles as they are congruent and supplementary.
Therefor, □ ABCD is a rectangle since a
parallelogram with one right interior angle is a rectangle.