Point, line, line segment aur ray mein kya fark hai?

Geometry ki neev

Geometry mein tum jo bhi aakaar padhoge, triangle se gole tak, wo kuch basic ideas se bante hain: points, line segments, lines aur rays. Angles ke saath milkar ye plane geometry ki neev banaate hain.

Point

Tez pencil se kaagaz par ek dot lagao. Nok jitni tez, dot utna patla. Ye chhota sa dot point ka idea deta hai: ek sateek jagah jiski na lambaai, na chaudaai, na oonchaai hoti hai. Compass ki nok, chhili hui pencil ka sira aur sui ki nok point ke models hain.

Jab kai points hon, to har ek ko ek capital letter se naam dete hain, jaise Z, P aur T, aur padhte hain ‘point Z’, ‘point P’ aur ‘point T’. Yaad rakho ki dot sateek jagahon ko dikhaate hain aur unhe bilkul patla samajhna chahiye.

Line segment

Kaagaz modkar kholo: crease se line segment ka idea milta hai. Ab do points A aur B lagao aur unhe alag raaston se jodo, seedha, ghumaavdaar ya tedha-medha. A se B tak ka sabse chhota raasta, A aur B samet, line segment AB hai. Ise AB ya BA likhte hain, letters ke upar ek chhoti line ke saath, aur A aur B iske end points hain. Line segment ki ek tay lambaai hoti hai jo ruler se naap sakte ho.

Line

Socho ki line segment AB ko A ke aage ek disha mein aur B ke aage doosri disha mein bina ant ke badhaaya gaya. Ye line hai. Line ka poora chitra kabhi nahi bana sakte, kyunki wo hamesha chalti hai; isliye dono siron par teer lagaate hain. A aur B se guzarti line ko AB likhte hain, letters ke upar dono taraf teer ke saath, ya ek chhote letter jaise l ya m se naam dete hain.

Do zaroori baatein:

• Do points se theek ek line ban sakti hai.
• Ek point se anginat lines ban sakti hain, har disha mein.

Ray

Ray line ka wo hissa hai jo ek point, apne starting point ya initial point, se shuru hokar ek disha mein bina ant ke chalta hai. Lighthouse ki roshni, torch ki roshni aur Suraj ki kiranein ray ke models hain.

Ray ka naam likhne ke liye pehle starting point aur phir us par koi aur point likho, upar teer ke saath: ray AP, A se shuru hokar P se guzarti hai. Kram zaroori hai:

• Agar ray OA, B se bhi guzarti hai, to use OB bhi keh sakte ho: wahi shuruaat, wahi disha.
• Par AO alag ray hai: wo A se shuru hokar O ki taraf jaati hai.

Chaaron ki tulna

	End points	Hamesha chalti hai?	Naam
Point	(ek jagah hai)	Nahi	P
Line segment	Do	Nahi	AB ya BA
Ray	Ek (starting point)	Ek disha mein	AP (shuruaat pehle)
Line	Koi nahi	Dono disha mein	AB ya l

Figures padhna

Book ki Fig. 2.4 mein paanch points kram se jude hain: L se M, M se P, P se Q aur Q se R. Line segments hain LM, MP, PQ aur QR. End points L aur R ek-ek segment par hain; M, P aur Q do-do par.

Fig. 2.5 mein teen points hain: T se ek ray par A, aur doosri par N aur B. Rays hain TA, TN aur TB, aur NB bhi ek ray hai. TA, TN aur TB ka starting point T hai, par NB ka nahi, wo N se shuru hoti hai. Dhyaan do ki TN aur TB ek hi raaste par ek hi disha mein jaati hain.

Khud karke dekho

1. Ek point lagao aur usse jitni lines bana sako banao. Kabhi khatam nahi hongi.
2. Do points lagao aur dono se guzarti do alag seedhi lines banaane ki koshish karo. Nahi bana paoge: sirf ek fit hoti hai.
3. Ek line l banao, us par points E aur F aur usse bahar point D lagao. Ab batao kaunse points l par hain.

Ye ideas seedhe angles tak le jaate hain, jo do rays se bante hain: dekho angle kya hai. Poore chapter ke liye Chapter 2 notes dekho.