Angles naapna

Class 6 Maths · Chapter 2: Lines aur Angles · NCERT Ganita Prakash section 2.9

Seekho

Angle ko number dene ke liye mathematicians ne ek point ke chaaron taraf ke poore chakkar ko 360 barabar hisson mein baanta. Har hissa 1 degree hai, likhte hain 1°. Yahan har tukda 10° hai, to teen tukde 30°.

3 × 10° = 30°

Poora chakkar 360° hai. Straight angle aadha chakkar: 180°. Right angle straight angle ka aadha: 90°.

360° → 180° → 90°

360 hi kyon? Bahut pehle log saal mein lagbhag 360 din ginte the, aur 360 ek dosti wala number hai: ise 2, 3, 4, 5, 6, 8, 9, 10 ya 12 barabar hisson mein baanta ja sakta hai.

360 ÷ 12 = 30°

Protractor 180 degree mein bata aadha circle hai. Iska centre vertex par rakho, ek arm ko 0 se milao, aur dekho doosri arm scale ko kahan kaatti hai. Lambe nishaan har 10°, beech wale har 5°.

50°

Protractor par numbers ki do lines hain: ek right mein 0 se shuru, doosri left mein 0 se. Hamesha usi 0 se gino jisse tumhari base arm mili hai.

130° (not 50°)

Protractor use karo: 135° ka angle banao.

Kaagaz ke circle ko baar-baar aadha modo: milte hain 180°, 90°, 45°, 22.5° … Har tah angle ko do barabar hisson mein kaatti hai. Ise angle ko bisect karna kehte hain, aur tah angle bisector hai.

90° ÷ 2 = 45°

Yaad rakho

• 1 poora chakkar = 360°. Straight angle = 180°. Right angle = 90°.
• Protractor: centre vertex par, ek arm 0 par, usi line ke numbers padho.
• Bisect matlab do barabar hisson mein kaatna; ye karne wali line angle bisector hai.

Quick check

Right angle mein kitne degree hote hain?

1. 45°
2. 90°
3. 180°
4. 360°

Socho

4 baje ghadi ki dono suiyon ke beech chhota angle kitna 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.