Khatisong ena, re tla hlahloba tlhaloso, lihlopha le thepa ea e 'ngoe ea libopeho tse kholo tsa geometri - khutlo-tharo. Re tla boela re hlahlobe mehlala ea ho rarolla mathata ho kopanya boitsebiso bo fanoeng.
Tlhaloso ea khutlotharo
Triangle - Ena ke setšoantšo sa geometri sefofaneng, se nang le mahlakoreng a mararo, a entsoeng ka ho kopanya lintlha tse tharo tse sa kang tsa robala molaong o le mong o otlolohileng. Letšoao le khethehileng le sebelisoa ho khetholla - △.
- Lintlha tsa A, B le C ke lithapo tsa khutlotharo.
- Likarolo tsa AB, BC le AC ke mahlakore a kgutlotharo, ao hangata a hlalosoang e le tlhaku e le 'ngoe ea Selatine. Ka mohlala, AB= a, BC = b, LE = c.
- Bokahare ba kgutlotharo ke karolo ya sefofane se tlamilweng ke mahlakore a kgutlotharo.
Mahlakore a kgutlotharo dintlheng a etsa dikgutlo tse tharo, ka tlwaelo di hlaloswa ka ditlhaku tsa Segerike - α, β, γ joalo-joalo Ka lebaka la sena, khutlotharo e boetse e bitsoa poligone e nang le likhutlo tse tharo.
Li-angles le tsona li ka hlalosoa ho sebelisoa letšoao le khethehileng "∠"
- α – ∠BAC kapa ∠CAB
- β – ∠ABC kapa ∠CBA
- γ – ∠ACB kapa ∠BCA
Sehlopha sa kgutlotharo
Ho latela boholo ba li-angles kapa palo ea mahlakore a lekanang, mefuta e latelang ea lipalo e khetholloa:
1. e hlobaetsang – kgutlotharo e nang le dikgutlo tse tharo tse bohale, ke hore ka tlase ho 90°.
2. boleo kgutlotharo eo e nngwe ya dikgutlo e leng kgolo ho feta 90°. Li-angles tse ling tse peli li bohale.
3. E ikhethang – kgutlotharo eo e nngwe ya dikgutlo e nepahetseng, ke hore, e lekana le 90°. Setšoantšong se joalo, mahlakore a mabeli a etsang angle e nepahetseng a bitsoa maoto (AB le AC). Lehlakore la boraro le shebaneng le lehlakoreng le nepahetseng ke hypotenuse (BC).
4. E sa tšoaneng khutlotharo eo mahlakore ohle a nang le bolelele bo fapaneng.
5. Li-Isosceles – kgutlotharo e nang le mahlakore a mabedi a lekanang, a bitswang lateral (AB le BC). Lehlakore la boraro ke setsi (AC). Setšoantšong sena, li-angles tsa motheo li lekana (∠BAC = ∠BCA).
6. Equilateral (kapa e nepahetse) kgutlotharo eo mahlakore ohle a leng bolelele bo lekanang. Hape li-angles tsohle tsa eona ke 60 °.
Thepa ea Triangle
1. Mahlakore afe kapa afe a kgutlotharo a ka tlase ho a mang a mabedi, empa a maholo ho feta phapang ya ona. Bakeng sa boiketlo, re amohela litlhaloso tse tloaelehileng tsa mahlakore - a, b и с… Joale:
b – c <a <b + cAt b > c
Thepa ena e sebelisetsoa ho lekola likarolo tsa mela ho bona hore na li ka etsa kgutlotharo.
2. Kakaretso ea li-angles tsa khutlotharo efe kapa efe ke 180°. Ho latela thepa ena hore ka har'a khutlotharo ea obtuse li-angles tse peli li lula li le matla.
3. Ho kgutlotharo leha e le efe, ho na le angle e khōloanyane e fapaneng le lehlakoreng le leholo, le ka tsela e fapaneng.
Mehlala ea mesebetsi
Mosebetsi 1
Ho na le likhutlo tse peli tse tsejoang ka har'a kgutlotharo, 32° le 56°. Fumana boleng ba angle ea boraro.
tharollo
Ha re nke li-angles tse tsejoang e le α (32°) le β (56 °), le tse sa tsejoeng - ka morao γ.
Ho ea ka thepa mabapi le kakaretso ea li-angles tsohle, a+b+c = 180 °.
Ka hona, γ = 180 ° – a – b = 180 ° - 32 ° - 56 ° = 92 °.
Mosebetsi 2
Ho fanoe ka likarolo tse tharo tsa bolelele ba 4, 8 le 11. Fumana hore na li ka etsa khutlotharo.
tharollo
A re theheng ho se lekane bakeng sa karolo ka 'ngoe ea likarolo tse fanoeng, ho latela thepa e boletsoeng ka holimo:
11 - 4 <8 <11 + 4
8 - 4 <11 <8 + 4
11 - 8 <4 <11 + 8
Kaofela ha tsona li nepahetse, ka hona, likarolo tsena li ka ba mahlakoreng a kgutlotharo.