The elu nke pyramid. Olee otú ịchọta ya?

Pyramid - a polyhedron, ndị isi nke bụ a polygon. All chere ihu n'aka ụdị triangles na izute otu vertex. Pyramid ndị zita, quadrilateral na na. Iji chọpụta ihe ndị pyramid n'ihu gị, ọ bụ zuru ezu iji gụọ ọnụọgụ nke akụkụ ya isi. The definition nke "elu nke pyramid" bụ nnọọ nkịtị na jiometrị na usoro ọmụmụ ebumnobi. Isiokwu a ga-agbalị na-atụle ụzọ dị iche iche nke-achọta ya.

pyramid akụkụ

Onye ọ bụla pyramid mejupụtara ndị na-esonụ ihe:

• n'akụkụ ihu nke nwere atọ n'akuku na converge na a vertex;
• apothem-anọchi anya elu na-arịdata site ya n'elu;
• n'elu nke pyramid - a mgbe na-ejikọ ndị mpụta n'ọnụ, ma nke a adịghị na-edina na ụgbọelu nke isi;
• isi - a polygon, nke na-abụghị nke n'ọnụ;
• elu nke pyramid bụ a nke na obe n'elu pyramid na ya isi Nleta a nri n'akuku.

Olee otú ịchọta elu nke pyramid, ọ bụrụ na ị maara ya olu

Mgbe usoro pyramid olu V = (S * h) / 3 (na usoro V - olu, S - ebe nke isi, h - elu nke pyramid), anyị na-ahụ na h = (3 * V) / S. Iji inokota ihe onwunwe, ka dozie nsogbu ozugbo. The zita pyramid square bases bụ 50 cm ^2, mgbe ya ibu bụ 125 cm ^3. Unknown elu nke a zita pyramid, na nke dị mkpa ka anyị chọta. Ọ bụ ihe dị mfe: fanye data n'ime anyị usoro. Anyị nweta h = (3 * 125) / 50 = 7.5 cm.

Olee otú ịchọta elu nke pyramid, ma ọ bụrụ na anyị maara na ogologo nke diagonal na ya n'ọnụ

Dị ka anyị na-echeta, elu nke pyramid na-eme ka ya na ya isi nri n'akuku. Nke a pụtara na ịdị elu nke ọgịrịga na ọkara diagonally ọnụ na-etolite a nri-angled triangle. Ọtụtụ, n'ezie, na-echeta Pythagorean Theorem. Ịmara abụọ nha, nke-atọ uru ga-adị mfe ịchọta. Cheta mara Theorem a² = b² + c², na ebe - na hypotenuse, na na nke a ihu pyramid; b - mbụ ụkwụ ma ọ bụ ọkara diagonal na - karị, nke abụọ ụkwụ ma ọ bụ dị elu nke pyramid. Site na nke a usoro c² = a² - b².

Ugbu a nsogbu: na nri diagonal nke pyramid bụ 20 cm, mgbe na ogologo nke ọnu - 30 cm elu ga-hụrụ .. Idozi: c² = 30² - 20² = 900-400 = 500. N'ihi ya, = √ 500 = banyere 22,4.

Olee otú ịchọta elu nke a truncated pyramid

Ọ bụ a polygon, nke nwere a ngalaba yiri ya isi. The elu nke a truncated pyramid - a nke na-ejikọ abụọ nke ya tọrọ ntọala ụwa. The elu nwere ike dị na mgbe pyramid, a ga-amara ma ọ bụrụ na ogologo nke diagonals nke abụọ bases, na kwa ihu pyramid. Ka diagonal ukwuu isi hà d1, mgbe nta diagonal ntọala - d2, na ọnu nwere ogologo - l. Iji chọta elu nwere ike ịbụ abụọ abụghị elu esereese ihe ala elu na ya isi. Anyị na-ahụ ihe anyị na-na na abụọ nri triangles, ọ na-anọgide na-ahụ na ogologo nke ụkwụ. N'ihi na nke a ukwuu diagonal nke a nta wepụ na ike site 2. Ebe ọ bụ na otu ụkwụ anyị na-ahụ: a = (d1-d2) / 2. Mgbe ahụ, dị ka Pythagorean Theorem, anyị nwere ike na-chọta nke abụọ ụkwụ, nke bụ ịdị elu nke pyramid.

Ugbu a anya na niile ikpe na omume. The ozi n'ihu anyị. The truncated pyramid nwere a square ke ukot, nke ukwuu isi nke diagonal ogologo bụ 10 cm, mgbe nta - 6 cm, na nku azu bụ hà 4 cm n'ịdị elu na-chọrọ iji chọta .. Iji chọta mmalite nke otu ụkwụ a = (10-6) / 2 = 2 cm Otu ụkwụ bụ hà 2 cm, na hypotenuse - 4 cm na-enyo na nke abụọ ụkwụ ma ọ bụ ịdị elu ga-hà 16-4 = 12, i.e. h = .. √12 = banyere 3.5 cm.