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2) à = 5 äì; b = 3 äì; special-edu.kz.

Ð = ;

3) à = 3 äì 2 ñì; b = 10 ñì;
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Ð =

.

Íàïèøèòå ôîðìóëó ïåðèìåòðà ïðÿ-

ìîóãîëüíèêà.

Ïðîâåðüòå ñåáÿ.

1) Ð = 2(6 + 4) =20 (ñì);

2) Ð = 2(5 + 3) =16 (ñì);
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3) Ð = 2(32 + 10) = 84 (ñì).

Ôîðìóëà ïåðèìåòðà ïðÿìîóãîëüíèêà:

Ð = 2à + 2b, èëè Ð = 2(à + b) ,

ãäå Ð – ïåðèìåòð ïðÿìîóãîëüíèêà,

à – äëèíà, b – øèðèíà ïðÿìîóãîëüíèêà.

Ïåðèìåòð ïðÿìîóãîëüíèêà ðàâåí
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óäâîåííîé ñóììå åãî äëèíû è øèðèíû.

Ôîðìóëà ïåðèìåòðà êâàäðàòà:

Ð = 4à ,

ãäå à – äëèíà ñòîðîíû êâàäðàòà

(ðèñ. 1.28).

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