Introduction to Three Dimensional Geometry Class 11 Notes Maths Chapter 12

These are the Introduction to Three Dimensional Geometry Class 11 Notes Maths Chapter 12 prepared by team of expert teachers. The revision notes help you revise the whole chapter 2 in minutes. Revision notes in exam days is one of the best tips recommended by teachers during exam days. Download CBSE Class 12 Maths Notes for chapter 12 in PDF format for free. https://meritbatch.com/introduction-to-three-dimensional-geometry-class-11-notes/

CBSE Class 11 Maths Notes Chapter 12 Introduction to Three Dimensional Geometry

Introduction To Three Dimensional Geometry Class 11 Notes
Coordinate Axes

In three dimensions, the coordinate axes of a rectangular cartesian coordinate system are three mutually perpendicular lines. These axes are called the X, Y and Z axes.

Coordinate Axes Notes

Coordinate Planes
The three planes determined by the pair of axes are the coordinate planes. These planes are called XY, YZ and ZX plane and they divide the space into eight regions known as octants.

Coordinate Planes Notes

Introduction To 3d Geometry Class 11 Notes
Coordinates of a Point in Space

The coordinates of a point in the space are the perpendicular distances from P on three mutually perpendicular coordinate planes YZ, ZX, and XY respectively. The coordinates of a point P are written in the form of triplet like (x, y, z).
The coordinates of any point on

  • X-axis is of the form (x, 0,0)
  • Y-axis is of the form (0, y, 0)
  • Z-axis is of the form (0, 0, z)
  • XY-plane are of the form (x, y, 0)
  • YZ-plane is of the form (0, y, z)
  • ZX-plane are of the form (x, 0, z)

Distance Formula
The distance between two points P(x1, y1, z1) and Q(x2, y2, z2) is given by
Class 11 Maths Introduction To Three Dimensional Geometry Notes

The distance of a point P(x, y, z) from the origin O(0, 0, 0) is given by
OP = \(\sqrt { { x }^{ 2 }+{ y }^{ 2 }+{ z }^{ 2 } }\)

Section Formula
The coordinates of the point R which divides the line segment joining two points P(x1, y1, z1) and Q(x2, y2, z2) internally or externally in the ratio m : n are given by
Introduction to Three Dimensional Geometry Class 11 Notes Maths Chapter 12 2

The coordinates of the mid-point of the line segment joining two points P(x1, y1, z1) and Q(x2, y2, z2) are
Introduction to Three Dimensional Geometry Class 11 Notes Maths Chapter 12 3

The coordinates of the centroid of the triangle, whose vertices are (x1, y1, z1), (x2, y2, z2) and (x3, y3, z3) are
Introduction to Three Dimensional Geometry Class 11 Notes Maths Chapter 12 4

NCERT Solutions