Mathematics · Class 11
Introduction to Three Dimensional Geometry
Learn Introduction to Three Dimensional Geometry with notes, examples, and practice questions.
2 sections15–25 min read6 MCQs · 2 examples
Chapter Overview
Introduces 3D coordinates (x,y,z), distance and section formulas in space — foundation for Class 12 vector algebra and 3D geometry.
Key Formulas
Distance
AB = √[(x₂−x₁)²+(y₂−y₁)²+(z₂−z₁)²]
Section (m:n)
((mx₂+nx₁)/(m+n), …)
Origin distance
√(x²+y²+z²)
Solved Examples
Step-by-step solutions — read each step before checking the final answer.
Distance
A(1,2,3), B(4,6,3).
- 1√(9+16+0)=5
Answer
5 units
Midpoint
Midpoint of above.
- 1((1+4)/2, (2+6)/2, 3)
Answer
(2.5, 4, 3)
Key Points to Remember
- ✓ Octants and sign of coordinates
- ✓ XY, YZ, ZX planes
- ✓ 2D formulas extend with z-term
Exam Tips
- • Don't forget z-coordinate in distance
- • Section formula same as 2D with z
Practice MCQs — Introduction to Three Dimensional Geometry
Test your understanding with topic-wise multiple choice questions. Explanations appear after each answer.
Question 1 of 6Score: 0/0
Distance from origin to (3,4,0):