Question

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2)Using the opposite angle test for parallelogram. Prove that every rectangle is parallelogram.​

Answer 1

Given:

Quadrilateral ABCD is a rectangle

To Prove:

Quadrilateral ABCD is a parallelogram

Proof:

Quadrilateral ABCD is a rectangle ................ (given)

Therefore Angle A = Angle B = Angle C = Angle D = 90°

Therefore Angle A = Angle C .......... (1)

Angle B = Angle D .......... (2)

Here angle A and angle C

and angle B and angle D are opposite angles

Therefore by (1) and (2) and using the opposite angle test Quadrilateral ABCD is a parallelogram

Hence proved

(A figure of rectangle can be drawn having name ABCD)