Ịgachi Pentagon: kacha nta ozi

Explanatory Dictionary Ozhegova na-ekwu na Pentagon bụ a geometric ọnụ ọgụgụ, ejedebeghị ise intersecting edoghi na-eme ka ise esịtidem akụkụ, nakwa dị ka ọ bụla ihe nke yiri udi. Ọ bụrụ na ihe niile n'akụkụ na akụkụ nke otu na a nyere polygon, ọ na-akpọ a nri (na Pentagon).

Gịnị bụ na-akpali mgbe nile Pentagon?

Ọ na-e n'ụdị a e wuru n'elu ma ama ụlọ nke United States Defense. Of olu nke mgbe polyhedrons naanị dodecahedron nwere ọnu n'ụdị Pentagon. Na ọdịdị na e nweghị kristal na niile, ndị mejupụtara nke ga-eyi a mgbe nile Pentagon. Ọzọkwa, a na ọnụ ọgụgụ bụ a polygon na a kacha nta ọnụ ọgụgụ nke akụkụ, nke bụ omume na-tile ebe. Naanị na ọnụ ọgụgụ nke diagonals nke Pentagon-ederịta akwụkwọ ozi na ọnụ ọgụgụ nke ya n'akụkụ. Kwere, nke a bụ na-akpali!

Basic Njirimara na nke usoro

Iji formulas maka ọ bụla mgbe polygon, ị nwere ike kọwaa niile dị mkpa kwa, nke bụ Pentagon.

• The Central n'akuku α = 360 / n = 360/5 = 72 Celsius.
• The n'ime n'akuku β = 180 Celsius * (n-2) / n = 180 Celsius * 3/5 = 108 Celsius. Ntem, nchikota nke ime akụkụ bụ 540 Celsius.
• The ruru nke diagonal ka mpụta n'akụkụ bụ hà (1 + √5) / 2, i.e. na "ọlaedo ngalaba" (ihe dị ka 1,618).
• Na ogologo nke dị n'akụkụ, nke nwere a mgbe nile Pentagon nwere ike gbakọọ site na otu nke atọ formulas, dabere na nke oke na-ama mara:

• ma ọ bụrụ na ọ na-akọwa a gburugburu gburugburu mara na okirikiri R, mgbe a = 2 * R * mmehie (α / 2) = 2 * R * mmehie (72 Celsius / 2) ≈1,1756 * R;
• mgbe c gburugburu okirikiri r ede a mgbe nile Pentagon, a = 2 * r * tg (α / 2) = 2 * r * tg (α / 2) ≈ 1,453 * r;
• ọ na-eme na kama mara ịdị ukwuu radii diagonal D, mgbe ahụ direction kpebisiri ike dị ka ndị a: a ≈ D / 1.618.

• The ebe nke a mgbe nile Pentagon-ekpebisi ike, ọzọ, Dabere na nke oke, anyị maara na:
• ma ọ bụrụ na e nwere na-dere ma ọ bụ circumscribed gburugburu, mgbe na-eji otu n'ime mmadụ abụọ formulas:

S = (n * a * r ) / 2 = 2,5 * a * r ma ọ bụ S = (n * R ² mmehie α) / 2 ≈ 2,3776 * R ^2;

• ebe nwekwara ike-ekpebisi ike site n'ịmara na n'akụkụ ogologo a:

S = (5 * a ² * tg54 Celsius) / 4 ≈ 1,7205 * a ^2.

Ịgachi Pentagon: ụlọ

Nke a geometric udi nwere ike wuru na ụzọ dị iche iche. Ka ihe atụ, ka dabara ya n'ime a gburugburu na a gaghị agara okirikiri dabeere na a gaghị agara Mee n'akụkụ. Usoro e kọwara na "Ihe" nke Euclid gburugburu 300 BC Na nke ọ bụla, anyị kwesịrị a compass na a onye na-achị. Tụlee eji a usoro iwu a gaghị agara gbaa.

1. Họrọ otu aka ike okirikiri, ma na-abịaru a gburugburu, nke na-anọchi ya center mgbe O.

2. On gburugburu akara, họrọ a mgbe na-arụ dị ka otu n'ime pinnacles anyị Pentagon. Ka a na-a mgbe A. Jikọọ ihe O na A akara nke.

3. Bịaruo a akara site na mgbe perpendicular na ogologo akara nkwonkwo. Ebe nrutu nke a ogologo akara na gburugburu akara dị ka uche B.

4. Ná n'etiti anya n'etiti ihe O na B Mee mgbe C.

5. Ugbu a isere a gburugburu onye center bụ na mgbe C na nke na-aga site na mgbe A. Position nke ya nrutu na ogologo akara Ob (ọ ga-abụ n'ime akpa gburugburu) bụ tụọ D.

6. rụọ a gburugburu site D, na etiti nke nke di na Area A of ya nrutu na mbụ gburugburu dị mkpa ka a mata isi ihe E na F.

7. Ugbu a na-ewu a gburugburu onye center bụ E. Iji mee nke a, ọ dị mkpa nke mere na ọ na-aga site A. Ọ bụ ebe ọzọ nke nrutu nke mbụ gburugburu dị mkpa Họpụtara Ịbụ ebe G.

8. N'ikpeazụ, rụọ a gburugburu na center A site na mgbe F. Mark ọzọ nrutu ebe nke mbụ gburugburu H.

9. Ugbu a ị naanị jikọọ n'elu A, E, G, H, F. anyị mgbe Pentagon ga-adị njikere!