Parallel Lines Kheenchna
Class 7 Maths · Chapter 5: Parallel aur Intersecting Lines · NCERT Ganita Prakash section 5.7
Seekho
Ruler aur set square se: line l kheencho. Set square ko l par khiskaakar uske right-angle kinaare se do lines kheencho. Dono l ke saath 90°. l ko transversal maano: corresponding angles barabar (90° aur 90°), to dono nayi lines parallel.
Diye bindu A se: set square ka ek kinaara l par rakho, doosre kinaare se ruler sataao, phir set square ko ruler ke saath A tak khiskaakar kheencho. Kinaara ruler ke saath poore raaste wahi angle rakhta hai, to corresponding angles barabar rehte hain.
Kaagaz modkar: silvat l aur bindu A ke liye, A se l ke perpendicular silvat t modo. Phir A se t ke perpendicular silvat m modo. l aur m dono t ke saath 90°: barabar corresponding angles, to l ∥ m.
l ⊥ t and m ⊥ t → l ∥ m
Dot paper par khadi, sapaat ya 45° lines aankh se ban jaati hain, par tirchhi lines mushkil. Aankh par bharosa karne ki jagah Neel angles se jaanchta hai: transversal barabar corresponding angles banaaye to lines sach mein parallel.
Explore: set square ke steps.
- A se parallel line kheenchne ke steps kram mein lagao.
Yaad rakho
- Ruler ke saath khiskta set square parallel lines kheenchta hai: corresponding angles barabar rehte hain.
- Ek hi line ke perpendicular do lines parallel hain.
Quick check
Do lines dono line t ke saath 90° banaati hain. Unke baare mein kya kah sakte ho?
- ve parallel hain
- ve aapas mein perpendicular hain
- ve t par milti hain
- kuch nahi
Answer
ve parallel hain. Barabar corresponding angles (90° aur 90°) matlab lines parallel.
Socho
Ek hi silvat t ke perpendicular modi do silvatein parallel kyun?
Ek answer
Dono t ke saath 90°. t ko transversal maano to ye barabar corresponding angles hain, isliye silvatein parallel.
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.