On augmente de 20% la longueur et on diminue de 20%la largeur d'un rectangle de dimension 30cm sur 20cm.
Quelle est en pourcentage la variation de son air?(justifier svp)

By: USER3826
28 Agustus 2025 mathematiques 5 minutes
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Question

Grade: Education Subject: mathematiques
On augmente de 20% la longueur et on diminue de 20%la largeur d'un rectangle de dimension 30cm sur 20cm.
Quelle est en pourcentage la variation de son air?(justifier svp)
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Answer (177)

Best Answer
(194)
bonjour,

A initiale = 30*20 = 600

Nouvelle aire =
L = 30*1,2  =36
l =30*0,8 = 24
36*24  =864

% d'évolution :
[(864-600)/600]*100 = 44%
Answered on 28 Agustus 2025

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