Sierpinski Triangle Aur Area Ka Khel | Class 8 Maths Book 2 Ch 4

πŸ“˜ Class 8 Β· Ganita Prakash Book 2Ch 4 Β· Exploring Some Geometric ThemesPost 2 / 9⏱ 25–30 min
Sierpinski Triangle Aur Area Ka Khel πŸ”Ί

βœ… Pehle Yeh Aata Hai?

Yeh post shuru karne se pehle, in teen sawaalon ko 1 minute mein khud try kijiye:

  1. 3 Γ— 3 Γ— 3 kitna hai?
  2. Equilateral triangle ke har angle kitne degree ke hote hain?
  3. (3/4) Γ— (3/4) = ?
Answers dekho
  1. 27
  2. 60Β°
  3. 9/16

Teeno sahi? Shaabaash! Carpet wala pattern yaad nahi? Post 1 β€” Fractals Kya Hain? dekh lijiye.

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🎬 Kahani: Rohan Ka Kaagaz Design

Rohan ki mummy ne ek bada tikona (triangle) kaagaz ka design banaane ko kaha. Rohan ne triangle ki teeno sides ke beech ke points jode, to andar 4 chhote triangles ban gaye.

β€œBeech wala ulta triangle kaat do,” Golu bola, β€œab 3 bache, har ek ke saath yahi karo!”

Kuch steps baad kaagaz pe ek jaali jaisa sundar design tha, jisme har triangle ke andar chhote triangles, unme aur chhote… Yeh hai Sierpinski Triangle (ya Sierpinski Gasket)! πŸ”Ί

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πŸ“– Concept: Midpoints Jodo, Beech Ka Hatao

Step 1: Banane ka tareeka

Ek equilateral triangle lo (Step 0). Teeno sides ke midpoints jodo: 4 ek jaise chhote equilateral triangles bante hain. Beech wala hata do (Step 1). Bache 3 triangles mein se har ek ke saath yahi karo (Step 2)…

Step 0Step 1Step 2Β© charumam.com
Sierpinski Triangle: har step pe har bache triangle ka beech wala hissa hat jaata hai.

Step 2: 4 triangles ek jaise kyun?

Kone ka chhota triangle dekho: uski do sides badi side ki aadhi-aadhi hain (midpoints se), to woh isosceles hai. Beech ka kona 60Β° hai, to baaki do kone (180 βˆ’ 60) Γ· 2 = 60Β°. Teeno kone 60Β°: yeh equilateral hai, side = aadhi.

Teeno kone wale triangles aise hi. Beech wale ki teeno sides bhi unhi ki sides hain, to woh bhi aadhi side ka equilateral. Chaaron ek jaise! βœ…

WHY yeh zaroori? Tabhi to β€œ4 barabar hisse, 1 hatao, 3 bache” sahi hai.

Step 3: Bache triangles (Tβ‚™)

Har bacha triangle agle step mein 3 deta hai: Tβ‚€ = 1, T₁ = 3, Tβ‚‚ = 9, T₃ = 27. Tβ‚™ = 3ⁿ.

Step 4: Ched (Hβ‚™)

Har bacha triangle 1 naya ched deta hai: Hβ‚™β‚Šβ‚ = Hβ‚™ + Tβ‚™.

Step n01234
Bache Tβ‚™1392781
Ched Hβ‚™0141340

Step 5: Bacha area

Har step mein har triangle ka 3/4 bachta hai (4 mein se 3). Shuru area 1 ho to Step n pe area = (3/4)ⁿ. Carpet mein (8/9)ⁿ tha.

WHY triangle jaldi ghatta hai? 3/4 = 0.75, jabki 8/9 β‰ˆ 0.89. Triangle har step mein 25% khota hai, carpet sirf ~11%.

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πŸ” Deep Concept: Ched Ka Seedha Formula

Hβ‚™ = 1 + 3 + 9 + … + 3ⁿ⁻¹. Iska jod = (3ⁿ βˆ’ 1) Γ· 2.

Kyun? S = 1 + 3 + … + 3ⁿ⁻¹. 3S = 3 + 9 + … + 3ⁿ. Ghatao: 3S βˆ’ S = 3ⁿ βˆ’ 1, to 2S = 3ⁿ βˆ’ 1. Check n = 3: (27 βˆ’ 1) Γ· 2 = 13 βœ…

Carpet ke liye bhi yahi chaal: Hβ‚™ = (8ⁿ βˆ’ 1) Γ· 7. Ek hi idea, do fractals! πŸ”

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✏️ Solved Examples

Example 1 (Easy): Step 5 pe bache triangles?

3⁡ = 243.

WHY sahi hai? 3 Γ— 3 Γ— 3 Γ— 3 Γ— 3 = 243 βœ…

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Example 2 (Medium): Step 5 pe ched?

Hβ‚… = Hβ‚„ + Tβ‚„ = 40 + 81 = 121.

WHY sahi hai? (3⁡ βˆ’ 1) Γ· 2 = 242 Γ· 2 = 121 βœ…

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Example 3 (NCERT style): Shuru triangle ka area 1 sq. unit. Step 3 pe bacha area?

(3/4)Β³ = 27/64 sq. unit β‰ˆ 0.42.

WHY sahi hai? 27 bache triangles, har ek ka area 1/64 βœ…

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Golu ka formula: β€œTriangle: bache 3ⁿ, area (3/4)ⁿ. Carpet: bache 8ⁿ, area (8/9)ⁿ!” πŸŽ‰

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🏠 Real Life Mein

  • 🎨 Rangoli aur kolam mein triangle ke andar triangle ke design.
  • πŸ›οΈ Purane Italian girjaghar: lagbhag 800 saal purane kuch farshon (Cosmati design) mein Sierpinski jaise triangles dikhte hain.
  • 🐚 Seepi (shell): kuch samudri seepiyon pe tikone patterns Sierpinski jaise dikhte hain.
  • πŸ’» Computer graphics: fractal patterns se pahaad aur ped banaaye jaate hain.

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🧭 Kab Use Karein, Kab Nahi

SituationKya kareinKyun
Equilateral ke midpoints jodoβœ… 4 barabar equilateral trianglesKone 60Β°, side aadhi
Bache trianglesβœ… 3ⁿHar triangle β†’ 3
Areaβœ… (3/4)ⁿ4 mein se 3 bachte
Ched ko 3ⁿ βˆ’ 1 likhna❌ Galat(3ⁿ βˆ’ 1) Γ· 2 hai

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βŒβ†’βœ… Worked Mistake

Sawaal: Step 2 pe bacha area (shuru 1)?

❌ Galat: β€œHar step ΒΌ hatta hai, to 1 βˆ’ ΒΌ βˆ’ ΒΌ = Β½.”

Galti kya hai? Step 2 mein jo hatta hai woh bache hue area ka ¼ hai, shuru ke area ka nahi ❌

βœ… Sahi:

  • Step 1: 3/4 bacha.
  • Step 2: 3/4 ka 3/4 = 9/16 β‰ˆ 0.56.

Yaad rakho: Fractal mein guna hota hai, ghatana nahi.

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πŸ“ 10 MCQs

Q1. Sierpinski triangle mein midpoints jodne se kitne triangles?

(a) 2
(b) 3
(c) 4
(d) 9
Solution dekho

Sahi jawab: (c)

  • (a) galat: Kam hain.
  • (b) galat: Bache 3 hain, bante 4.
  • (c) sahi: 4 ek jaise βœ…
  • (d) galat: 9 Step 2 ke bache hain.

Q2. T₃ = ?

(a) 9
(b) 27
(c) 81
(d) 13
Solution dekho

Sahi jawab: (b)

  • (a) galat: Tβ‚‚ hai.
  • (b) sahi: 3Β³ βœ…
  • (c) galat: Tβ‚„ hai.
  • (d) galat: H₃ hai.

Q3. H₃ = ?

(a) 13
(b) 9
(c) 27
(d) 4
Solution dekho

Sahi jawab: (a)

  • (a) sahi: 1 + 3 + 9 βœ…
  • (b) galat: Tβ‚‚.
  • (c) galat: T₃.
  • (d) galat: Hβ‚‚.

Q4. Step 2 area (shuru 1)?

(a) 1/2
(b) 9/16
(c) 3/4
(d) 27/64
Solution dekho

Sahi jawab: (b)

  • (a) galat: Ghatana galat.
  • (b) sahi: (3/4)Β² βœ…
  • (c) galat: Step 1.
  • (d) galat: Step 3.

Q5. Kone wala chhota triangle equilateral kyun?

(a) Isosceles + 60Β° kona
(b) Andaaza
(c) Bada hai
(d) Kyunki gol hai
Solution dekho

Sahi jawab: (a)

  • (a) sahi: Baaki kone bhi 60Β° βœ…
  • (b) galat: Saboot hai.
  • (c) galat: Size se nahi.
  • (d) galat: Galat.

Q6. Kaun jaldi area khota hai?

(a) Carpet
(b) Triangle
(c) Dono same
(d) Koi nahi
Solution dekho

Sahi jawab: (b)

  • (a) galat: 8/9 β‰ˆ 0.89 bachta.
  • (b) sahi: 3/4 = 0.75 bachta βœ…
  • (c) galat: Alag hai.
  • (d) galat: Dono khote hain.

Q7. Hβ‚™ ka formula?

(a) 3ⁿ
(b) (3ⁿ βˆ’ 1)/2
(c) 3n
(d) (3ⁿ + 1)/2
Solution dekho

Sahi jawab: (b)

  • (a) galat: Yeh bache hain.
  • (b) sahi: Sahi βœ…
  • (c) galat: Linear nahi.
  • (d) galat: +1 galat.

Q8. Chhote triangle ki side (shuru 16 cm), Step 2?

(a) 8 cm
(b) 4 cm
(c) 2 cm
(d) 12 cm
Solution dekho

Sahi jawab: (b)

  • (a) galat: Step 1.
  • (b) sahi: 16 β†’ 8 β†’ 4 βœ…
  • (c) galat: Step 3.
  • (d) galat: Galat.

Q9. Tβ‚„ = ?

(a) 64
(b) 81
(c) 243
(d) 12
Solution dekho

Sahi jawab: (b)

  • (a) galat: 4Β³.
  • (b) sahi: 3⁴ βœ…
  • (c) galat: 3⁡.
  • (d) galat: Galat.

Q10. Step 1 mein kaun sa triangle hataate hain?

(a) Upar wala
(b) Beech wala (ulta)
(c) Baayein wala
(d) Koi nahi
Solution dekho

Sahi jawab: (b)

  • (a) galat: Kone wale bachte hain.
  • (b) sahi: Beech ka βœ…
  • (c) galat: Kone wale bachte hain.
  • (d) galat: Ek hatta hai.

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❓ FAQs (Bachchon Ke Asli Sawaal)

1. Gasket aur triangle same hai?

Haan, Sierpinski Gasket aur Sierpinski Triangle ek hi cheez ke naam hain.

2. Kya kisi bhi triangle se bana sakte hain?

Midpoints jodne se hamesha 4 barabar triangles bante hain, par β€œequilateral” wala design sabse sundar aur NCERT wala hai.

3. Ched ka formula yaad kaise rakhein?

Bache βˆ’ 1, phir 2 se bhaag: (3ⁿ βˆ’ 1) Γ· 2.

4. Area kabhi zero hota hai?

Nahi, (3/4)ⁿ hamesha zero se bada, par chhota hota jaata hai.

5. Kitne steps tak draw karein?

Kitaab Step 2 tak kehti hai. Step 3–4 tak bahut sundar dikhta hai!

6. Perimeter ka kya hota hai?

Kul perimeter badhta hai: har step pe 3/2 guna (Olympiad dekho).

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πŸ‹οΈ Practice Zone (12 Sawaal)

Q1. Easy Tβ‚‚ aur Hβ‚‚?

Solution dekho

9 aur 4.

Q2. Easy Step 1 mein kitne ched?

Solution dekho

1.

Q3. Easy Step 3 mein naye ched kitne bane?

Solution dekho

Tβ‚‚ = 9.

Q4. Easy Step 1 area?

Solution dekho

3/4.

Q5. Medium T₆?

Solution dekho

729.

Q6. Medium H₆?

Solution dekho

(729 βˆ’ 1) Γ· 2 = 364.

Q7. Medium Step 4 area?

Solution dekho

81/256 β‰ˆ 0.32.

Q8. NCERT style Step 2 tak draw karo, bache aur ched gino.

Solution dekho

9 bache, 4 ched.

Q9. NCERT style Dikhao midpoint triangles equilateral hain.

Solution dekho

Kone wala: 2 sides aadhi (isosceles) + 60Β° β†’ baaki 60Β°, 60Β°. Equilateral.

Q10. Medium Shuru side 32 cm. Step 3 mein chhote triangle ki side?

Solution dekho

32 Γ· 8 = 4 cm.

Q11. Medium Kab bacha area 1/4 se kam?

Solution dekho

(3/4)⁴ β‰ˆ 0.316, (3/4)⁡ β‰ˆ 0.237. Step 5.

Q12. NCERT style Har Sierpinski fractal ka Step n area batao.

Solution dekho

Carpet (8/9)ⁿ, Triangle (3/4)ⁿ.

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🧠 HOTS (Sochne Wale Sawaal)

Q1. Step n pe ek chhote triangle ka area kitna (shuru 1)?

Solution dekho

(1/4)ⁿ. Kul = 3ⁿ Γ— (1/4)ⁿ = (3/4)ⁿ βœ…

Q2. Kya Hβ‚™ + Tβ‚™ = Hβ‚™β‚Šβ‚ se Hβ‚™β‚Šβ‚ ka formula nikalta hai?

Solution dekho

(3ⁿ βˆ’ 1)/2 + 3ⁿ = (3ⁿ⁺¹ βˆ’ 1)/2 βœ…

Q3. Golu kehta hai Step 10 pe area 0 ho jaayega. Sahi?

Solution dekho

(3/4)¹⁰ β‰ˆ 0.056, zero nahi.

Q4. Hataaye gaye triangles ka kul area Step n tak?

Solution dekho

1 βˆ’ (3/4)ⁿ.

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πŸ† Olympiad Corner

Q1. Shuru perimeter 3 (side 1). Step n pe saare bache triangles ki kul perimeter?

Solution dekho

3ⁿ triangles Γ— 3 Γ— (1/2)ⁿ = 3 Γ— (3/2)ⁿ. Badhti jaati hai!

Q2. Kitne step mein ched 100 se zyada?

Solution dekho

Hβ‚… = 121. Step 5 (Hβ‚„ = 40).

Q3. Step 3 ke ched ke alag-alag size kitne?

Solution dekho

3 size: Step 1 ka bada (1), Step 2 ke (3), Step 3 ke (9).

Q4. Tβ‚‚β‚€ ka aakhri digit?

Solution dekho

3ⁿ ke aakhri digit 3, 9, 7, 1 repeat. 20 β†’ 1.

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πŸ’— CharuMam Motivation

Rohan ne sirf ek chhota sa niyam baar-baar lagaaya, aur ek jaali jaisa adbhut design ban gaya. πŸ”Ί

Badi uplabdhiyaan aksar ek chhote niyam ko baar-baar, dhairya se dohraane se aati hain. Aaj ka chhota kadam, kal ka sundar pattern! 🌟

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🟒 Master Recap

  • Equilateral triangle ke midpoints jodo β†’ 4 barabar equilateral triangles.
  • Beech wala hatao, har bache triangle pe repeat.
  • Bache: Tβ‚™ = 3ⁿ. Ched: Hβ‚™β‚Šβ‚ = Hβ‚™ + Tβ‚™ = (3ⁿ βˆ’ 1) Γ· 2.
  • Area: (3/4)ⁿ (carpet (8/9)ⁿ se jaldi ghatta).
  • Fractal mein har step guna se chalta hai.

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πŸ‘‰ Aage Kya?

Ab ek aisa fractal jiska area badhta hai par ek seema mein rehta hai, aur perimeter anant ho jaata hai: Koch Snowflake! ❄️

Koi doubt? CharuMam AI Tutor se poochho, ya comment mein likho! πŸ’¬

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