Perimeter

Class 6 Maths · Chapter 6: Perimeter aur Area · NCERT Ganita Prakash section 6.1

Seekho

Kisi band shape ka perimeter uski boundary ke chaaron taraf ek baar ghoomne ki poori doori hai. Chalo is rectangle ke kinare-kinare chalte hain. Har chhote square ki side 1 cm hai.

Upar chalo: 5 cm. Phir right side neeche: 3 cm. Ab tak 5 + 3 = 8 cm.

5 + 3 = 8 cm

Neeche (5 cm) aur left side upar (3 cm), aur hum wapas start par. Length aur breadth dono do-do baar aate hain.

5 + 3 + 5 + 3 = 2 × (5 + 3) = 16 cm

Rectangle ABCD 9 cm lamba aur 6 cm chauda hai. Rectangle ki aamne-saamne ki sides barabar hoti hain (AB = CD, BC = AD), isliye rectangle ka perimeter = 2 × (lambai + chaudai).

2 × (9 + 6) = 2 × 15 = 30 cm

Aditi 20 cm side wale square greeting card ke chaaron or ribbon lagati hai. Square ki chaaron sides barabar hain, isliye jodne ki jagah guna karte hain: square ka perimeter = 4 × side.

4 × 20 cm = 80 cm of ribbon

Triangle ke liye uski teeno sides jodo. 6 cm, 8 cm aur 9 cm sides wale triangle ka perimeter 23 cm hai.

6 + 8 + 9 = 23 cm

Regular polygons ki saari sides barabar hoti hain, jaise equilateral triangle. To perimeter = sides ki ginti × ek side ki lambai.

Kabir 60 m side wale square maidan ke 4 chakkar lagata hai. Ek chakkar perimeter hai: 4 × 60 = 240 m. Chaar chakkar: 4 × 240 = 960 m.

4 × 240 m = 960 m

Ab tumhari baari! Length aur breadth badlo. Coral line perimeter hai. Kya tum mission poora kar sakte ho?

Yaad rakho

• Polygon ka perimeter = saari sides ka jod.
• Rectangle: 2 × (length + breadth). Square: 4 × side. Equilateral triangle: 3 × side.

Quick check

Ek rectangle 7 cm lamba aur 3 cm chauda hai. Iska perimeter kitna hai?

1. 10 cm
2. 20 cm
3. 21 cm
4. 21 sq cm

Socho

Ek square aur ek rectangle dono ka perimeter 24 cm hai. Rectangle 8 cm lamba hai. Kaun si shape zyada jagah gherti hai?

Practice

Teen levels (easy, medium, hard) ke naye sawaalon se practice karo, kuch hands-on, hints aur hal ke saath. Topic poora karne ke liye pichhle 5 mein se 4 sahi karo.