Question

Using opposite angle test for parallelogram prove that every rectangle is a parallelogram ​

Answer 1

Answer:

In parallelogram,

Opposite sides and angles are equal.

So in rectangle opposite angle are 90⁰ and sides are equal.

So every rectangle is a parallelogram but every parallelogram is not a rectangle.

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Answer 2

Answer:

At firstwe can easily prove that ABM ≡ CDM using the SAS congruence test. (alternate angles are equal).

Hence, ABCD is a parallelogram, because one pair of opposite sides are equal and parallel.

Thereafter, ABCD is also a rectangle, because it is a parallelogram with one right angle.

Step-by-step explanation:

Given : ABCD is rectangle.

To Prove : ABCD is a parallelogram.

Proof : ABCD is a rectangle.

A = B = C = D = 90°........( angle of a rectangle )

In ABCD,

A = C } Opposite angle

B = D } are congruent.

ABCD is a parallelogram.......( property of parallelogram )