Introduction to Three Dimensional Geometry Class 11 Maths Notes – Formulas & Quick Revision

3D Geometry ka intro chapter — coordinate axes, distance aur section formula in 3D. Chhota aur poora scoring. Yahan aapko is chapter ke sabse important formulas aur quick revision points free milte hain — NCERT/CBSE syllabus ke hisaab se, boards aur JEE/NEET dono ke liye.

Important Formulas & Concepts — Introduction to Three Dimensional Geometry

• Distance: √[(x₂−x₁)² + (y₂−y₁)² + (z₂−z₁)²]
• Section formula (internal): ((mx₂+nx₁)/(m+n), …)
• Midpoint: ((x₁+x₂)/2, (y₁+y₂)/2, (z₁+z₂)/2)
• Centroid of triangle: ((x₁+x₂+x₃)/3, …)
• XY-plane par z = 0; YZ par x = 0; ZX par y = 0
• Octants: 8 regions, signs se identify
• x-axis par point: (x, 0, 0)
• External division: ((mx₂−nx₁)/(m−n), …)

Quick Revision Points

• Axes par aur planes par points ke coordinates ka pattern yaad rakho
• Collinearity: distances ka sum check ya section formula
• Ratio nikalne ke questions mein k:1 assume karo
• Ye chapter Class 12 ke 3D ka base hai
• 15-minute revision, full marks

FAQ

Ye chapter kitna time du?

Kam — formulas seedhe hain. PDF ka one-page sheet kaafi hai.

Class 12 3D se kya connection?

Direction cosines aur lines/planes Class 12 mein isi foundation par aate hain.

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