Ke ʻimi nei i kahi o kahi triangle: ʻano a me nā laʻana

triangle – He kiʻi geometric kēia i ʻekolu ʻaoʻao i hana ʻia ma ka hoʻohui ʻana i ʻekolu mau kiko ma ka mokulele ʻaʻole pili i ka laina pololei like.

Nā ʻōkuhi maʻamau no ka helu ʻana i ka ʻāpana o kahi triangle

Ke kumu a me ke kiʻekiʻe

Pahu (S) o ka huinakolu, ua like ia me ka hapalua o ka huina hoonui o kona kumu a me kona kiekie.

ʻO ke kumumanaʻo Heron

No ka huli ʻana i kahi (S) o ka huinakolu, pono e ike i ka loa o kona mau aoao a pau. Ua manaoia penei:

p – semi-puni o kahi huinakolu:

Ma nā ʻaoʻao ʻelua a me ke kihi ma waena o lākou

ʻĀpana o kahi huinakolu (S) ua like ia me ka hapalua o ka hoonui o kona mau aoao elua a me ka sine o ka huina mawaena o laua.

Ka ʻāpana o ka huinakolu ʻākau

Pahu (S) o kekahi kii ua like ia me ka hapalua o ka hua o kona mau wawae.

Kahi o kahi triangle isosceles

Pahu (S) ua helu ʻia me ka hoʻohana ʻana i kēia ʻano:

Ka ʻāpana o kahi huinakolu kaulike

No ka ʻike ʻana i ka ʻāpana o kahi triangle maʻamau (ua like nā ʻaoʻao a pau o ke kiʻi), pono ʻoe e hoʻohana i kekahi o nā kumu ma lalo nei:

Ma o ka loa o ka aoao

Ma o ke kiekie

Nā laʻana o nā hana

Hana 1

E huli i ka ʻāpana o ka huinakolu inā he 7 knm kekahi o kona mau aoao a he 5 knm ke ki'eki'e.

Hoʻoholo:

Hoʻohana mākou i ke ʻano e pili ana ka lōʻihi o ka ʻaoʻao a me ke kiʻekiʻe:

S = 1/2 ⋅ 7 knm ⋅ 5 knm = 17,5 knm².

Hana 2

E imi i ka apana o ka huinakolu nona na aoao he 3, 4 a me 5 knm.

1 Haʻina:

E hoʻohana kākou i ke ʻano o Heron:

Ke ʻāpana ʻāpana (p) = (3 + 4 + 5) / 2 = 6 knm.

ʻO ke kumu iho, ʻo S = √6(6-3)(6-4)(6-5) = 6 knm².

2 Haʻina:

No ka mea, o ka huinakolu me na aoao 3, 4 a me 5, he huinaha like ia, ua hiki ke heluia kona wahi me ka hoohana ana i ke kumu hoohalike:

S = 1/2 ⋅ 3 knm ⋅ 4 knm = 6 knm².