Kupeza dera la makona atatu: chilinganizo ndi zitsanzo

Triangle - Ichi ndi chithunzi cha geometric chomwe chimakhala ndi mbali zitatu zomwe zimapangidwira pogwirizanitsa mfundo zitatu pa ndege yomwe siili ya mzere wowongoka womwewo.

General mafomula kuwerengera dera la makona atatu

Maziko ndi kutalika

Chigawo (S) ya makona atatu ndi ofanana ndi theka lachinthu cha maziko ake ndi kutalika kwake.

Fomula ya Heron

Kuti mupeze malo (S) ya makona atatu, muyenera kudziwa kutalika kwa mbali zake zonse. Zimaganiziridwa motere:

p - semi-perimeter ya makona atatu:

Kupyolera mu mbali ziwiri ndi ngodya pakati pawo

Chigawo cha makona atatu (S) ndi wofanana ndi theka la chinthu cha mbali zake ziwiri ndi sine wa ngodya pakati pawo.

Dera la makona atatu kumanja

Chigawo (S) yachifaniziro ndi yofanana ndi theka la chinthu cha miyendo yake.

Dera la makona atatu a isosceles

Chigawo (S) imawerengedwa pogwiritsa ntchito njira iyi:

Chigawo cha makona atatu ofanana

Kuti mupeze dera la makona atatu (mbali zonse za chithunzicho ndi zofanana), muyenera kugwiritsa ntchito imodzi mwa njira zomwe zili pansipa:

Kupyolera mu utali wa mbali

Kupyolera mu utali

Zitsanzo za ntchito

Ntchito 1

Pezani dera la makona atatu ngati mbali imodzi ndi 7 cm ndipo kutalika kwake ndi 5 cm.

Kusankha:

Timagwiritsa ntchito njira yomwe kutalika kwa mbali ndi kutalika kumakhudzidwa:

S = 1/2 ⋅ 7 cm ⋅ 5 cm = 17,5 cm².

Ntchito 2

Pezani dera la makona atatu omwe mbali zake ndi 3, 4 ndi 5 cm.

1 Yankho:

Tiyeni tigwiritse ntchito njira ya Heron:

Semiperimeter (p) = (3 + 4 + 5) / 2 = 6 cm.

Zotsatira zake, S = √6(6-3)(6-4)(6-5) = 6 masentimita².

2 Yankho:

Chifukwa makona atatu omwe ali ndi mbali 3, 4 ndi 5 ndi amakona anayi, dera lake likhoza kuwerengedwa pogwiritsa ntchito ndondomeko yofanana:

S = 1/2 ⋅ 3 cm ⋅ 4 cm = 6 cm².