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Chapter 9 Class 11 Straight Lines

Master Chapter 9 Class 11 Straight Lines with comprehensive NCERT Solutions, Practice Questions, MCQs, Sample Papers, Case Based Questions, and Video lessons.

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Updated for new NCERT 2026-2026.

Get solutions of Chapter 9 Class 11 Straight Lines of the NCERT Book. Answers of all exercise questions, examples and miscellaneous are provided for your reference.

 

Let's see what this chapter is all about.

We learned about Coordinate Geometry in Class 10. In this chapter, we will

  • Revise our Coordinate Geometry concepts (Distance between points, Section Formula, Area of triangle) and solve some questions 
  • What is slope of a line, and different methods to find it (angle, 2 points)
  • Finding angle between two lines using slope
  • Checking if lines are parallel or perpendicular, using slope
  • Proving three points collinear using slope (Slope of AB = Slope of BC)
  • Then, we study equation of lines
  • Equation of lines parallel to x and y axis
  • Slope of lines parallel to x and y axis
  • Equation of line when 1 point and slope is given
  • Equation of line when 2 points are given
  • Equation of line when slope and intercept is given(both x intercept and y intercept)
  • Equation of line when both x and y intercepts are given (Equation of line in intercept form)
  • Equation of line in normal form
  • General Equation of line, and converting any equation into General Form
  • Finding Distance of a point from the line
  • Finding Distance between two parallel lines
  • Distance of a point from a line along a line
  • Mix Questions using all the concepts

 

You can check out the solutions by clicking the exercise links below, or learn the concepts (with questions), the NCERT way.

Serial order wise

Ex 9.1 Start Learning
Ex 9.2 Start Learning
Ex 9.3 Start Learning
Examples Start Learning
Miscellaneous Start Learning

Concept wise

Cordinate geometry questions Start Learning
Slope - Finding slope Start Learning
Slope - Prependicularity Start Learning
Angle between two lines by Slope Start Learning
Collinearity of 3 points by sliope Start Learning
Point Slope form Start Learning
Slope-Intercept form Start Learning
Intercept form Start Learning
Normal form Start Learning
Given Statement Start Learning
Two lines // or/and prependicular Start Learning
Angle between two lines Start Learning
Distance - Between two parallel lines Start Learning
Distance of a point from a line Start Learning
Distance of a point from a line along a line Start Learning
Other Type of questions - Area of Triangle formed Start Learning
Other Type of questions - 3 lines Concurrent Start Learning
Other Type of questions - Image Start Learning
Other Type of questions - Mix Start Learning

Why Learn This With Teachoo?

Updated for new NCERT 2026-2026.

Get solutions of Chapter 9 Class 11 Straight Lines of the NCERT Book. Answers of all exercise questions, examples and miscellaneous are provided for your reference.

 

Let's see what this chapter is all about.

We learned about Coordinate Geometry in Class 10. In this chapter, we will

  • Revise our Coordinate Geometry concepts (Distance between points, Section Formula, Area of triangle) and solve some questions 
  • What is slope of a line, and different methods to find it (angle, 2 points)
  • Finding angle between two lines using slope
  • Checking if lines are parallel or perpendicular, using slope
  • Proving three points collinear using slope (Slope of AB = Slope of BC)
  • Then, we study equation of lines
  • Equation of lines parallel to x and y axis
  • Slope of lines parallel to x and y axis
  • Equation of line when 1 point and slope is given
  • Equation of line when 2 points are given
  • Equation of line when slope and intercept is given(both x intercept and y intercept)
  • Equation of line when both x and y intercepts are given (Equation of line in intercept form)
  • Equation of line in normal form
  • General Equation of line, and converting any equation into General Form
  • Finding Distance of a point from the line
  • Finding Distance between two parallel lines
  • Distance of a point from a line along a line
  • Mix Questions using all the concepts

 

You can check out the solutions by clicking the exercise links below, or learn the concepts (with questions), the NCERT way.