Lagnever AI English

Angle kya hai?

Short mein jawab

Angle do rays se banta hai jo ek hi point se shuru hoti hain. Common starting point vertex hai aur dono rays arms hain. ∠DBE ka vertex B aur arms BD aur BE hain. Angle ka size vertex ke chaaron or ek arm se doosri tak ka ghumaav hai, arms ki lambaai nahi.

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Do rays aur ek vertex

Angle do rays se banta hai jinka starting point ek hi ho. Figure mein rays BD aur BE dono B se shuru hoti hain. Point B angle ka vertex hai, aur rays BD aur BE iski arms hain.

Vertex B aur arms BD aur BE waala angle DBE, jiska naam ∠DBE ya ∠EBD
Angle ke hisse

Angle ka naam

Ise bas angle B keh sakte hain. Zyaada saaf karne ke liye har arm par ek point aur vertex lete hain: angle DBE ya angle EBD, likhte hain ∠DBE ya ∠EBD. Vertex hamesha beech ka letter hota hai. Vertex par bana chhota curve batata hai kaunsa angle matlab hai.

Teen letters tab zaroori hain jab kai angles ek vertex share karein. Agar rays PA, PB aur PC sab P se shuru hon, to P par teen angles hain: ∠APB, ∠BPC aur ∠APC. ∠P likhne se pata nahi chalega kaunsa, isliye ∠APB ko ∠P nahi likh sakte.

Angle ka size ek ghumaav hai

Vidya ko kitaab ka cover kholte dekho. Pehle cover thoda sa uthta hai; phir aur zyaada, jab tak wo mez par seedha na let jaaye, aur aakhir mein jab wo kitaab haath mein pakadkar likhne ke liye cover poora peeche mod deti hai. Har baar cover aur panno ke beech ka angle badhta hai, kyunki wo cover ko zyaada ghumaati hai.

Angle ka size ek ray ki shuruaati se aakhri sthiti tak ka ghumaav hai: chauthaai chakkar 90°, aadha 180° aur poora 360°
Ghumaav ki maatra

Jaise line segment ka size uski lambaai se batate hain, waise hi angle ka size uske ghumaav se: vertex ke chaaron or pehli ray ko doosri tak le jaane ke liye zaroori ghumaav.

Hamaare aas-paas ke angles

Jahan bhi ek hissa doosre ke muqaable ghoomta hai, wahan angle banta hai:

  • Compass ya divider mein arms jod ke chaaron or ghoomti hain; jod vertex hai.
  • Kainchi screw ke chaaron or khulti hai; blades arms hain.
  • Chashma, batua, stapler, pencil box aur dibbe ka dhakkan, sab khulkar angles banaate hain.
  • Cycle ke frame mein jahan tubes milti hain wahan angles bante hain, jaise pedal ke jod D par ∠BDC.

Angles ki tulna

Kuch angles dekhkar hi pehchaan mein aa jaate hain, jaise jaanwaron ka munh kam ya zyaada khulna. Par 89° aur 91° lagbhag ek jaise dikhte hain, isliye ek tareeka chahiye.

Superimposition: ek angle trace karo aur doosre par aise rakho ki vertex mil jaayein aur ek arm doosri arm par aa jaaye. Jis angle ki doosri arm bahar rahe, wo bada hai. Agar doosri arms bhi ek-doosre par aa jaayein, to angles barabar hain: dono mein utna hi ghumaav chahiye.

Superimposition se angles ki tulna: angle PQR, angle ABC se bada hai; alag lambaai ki arms waale do 45° ke angles barabar hain
Angles ki tulna

Bina trace kiye: ek angle ke vertex par paardarshi gole ka centre rakho, jahan arms gole ko kaatti hain wahan nishaan lagao, phir gole ko doosre angle par le jaao. Book isi se tay karti hai ki kaunsa saaras (crane) chonch zyaada kholta hai.

Arms ki lambaai se fark nahi padta

Do kaagaz ki straws aur ek paper clip se ‘rotating arms’ banao, alag angles par set karo, aur cardboard mein kaati angle ke aakaar ki slit se nikaalne ki koshish karo. Sirf wahi jodi nikalti hai jiska angle slit se bilkul milta hai, straws kitni bhi lambi hon. Yaani angle ki arms kitni bhi lambi banao, angle wahi rehta hai.

Points se angles ginna

Teen points A, B aur C, jo ek line par na hon, lagao aur har jodi se line banao: 3 lines (AB, BC, CA) milti hain aur 3 angles ke naam likh sakte ho: ∠ABC, ∠BCA aur ∠CAB. Chaar points, jinme koi teen ek line par na hon, se 6 lines milti hain aur 12 angles ke naam likh sakte ho, har point par teen.

Aage, angles ko size ke hisaab se kaise group karte hain ye angles ke types mein padho, ya Chapter 2 notes par waapas jaao.

Practice karo

  1. ∠XYZ ki arms kaunsi hain?

    1. (a) XY aur XZ
    2. (b) YX aur YZ
    3. (c) ZX aur ZY
    4. (d) sirf XZ
    Jawab dekho

    Jawab: (b) YX aur YZ

  2. Angle ka size kis pe nirbhar hai?

    1. (a) arms ki lambaai
    2. (b) arms ke beech ka ghumaav
    3. (c) lines ki motaai
    4. (d) letters
    Jawab dekho

    Jawab: (b) arms ke beech ka ghumaav

  3. Teen points A, B, C ek line par nahi hain. Sirf inhi letters se kitne angles ke naam likh sakte ho?

    1. (a) 1
    2. (b) 2
    3. (c) 3
    4. (d) 6
    Jawab dekho

    Jawab: (c) 3

  4. Rays PA, PB aur PC, P se shuru hoti hain. ∠APB ko ∠P kyun nahi keh sakte?

    Jawab dekho

    Jawab: Teen angles ka vertex P hai: ∠APB, ∠BPC aur ∠APC. ∠P likhne se pata nahi chalega kaunsa, isliye teen letters chahiye.

  5. Khuli kainchi ke blades se bane angle ki arms aur vertex batao.

    Jawab dekho

    Jawab: Vertex wo screw hai jahan blades jude hain; dono blades arms hain.

Students ke sawal

Angle kya hai?

Angle do rays se banta hai jinka starting point ek hi ho. Starting point vertex kehlaata hai aur rays arms. Iska size vertex ke chaaron or ek arm ko doosri tak le jaane ka ghumaav hai.

Angle ka naam kaise likhte hain?

Har arm par ek point lekar vertex ko beech mein rakho, jaise rays BD aur BE ke beech B waale angle ke liye ∠DBE ya ∠EBD. Agar us vertex par ek hi angle ho, to ∠B kaafi hai. Vertex par chhota curve dikhaata hai kaunsa angle hai.

Do angles ki tulna kaise karein?

Superimposition se: ek angle trace karke doosre par aise rakho ki vertex aur ek jodi arms mil jaayein. Jis angle ki doosri arm bahar rahe, wo bada hai. Vertex par centre waala paardarshi gola bhi use kar sakte ho.

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