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प्रश्न
In parallelogram ABCD, ∠A = 90°
(i) What is the measure of angle B.
(ii) Write the special name of the parallelogram.
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उत्तर
In parallelogram ABCD, ∠A = 90°

(i) ∵ In a parallelogram, adjacent angles are supplementary
∴ ∠A + ∠B = 180°
⇒ 90° + ∠B = 180°
⇒ ∠B = 180° - 90°
⇒ ∠B = 90°
(ii) The name of the given parallelogram is a rectangle.
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