NCERT Solutions for Ganita Prakash (Part 1) Chapter 5 Parallel and Intersecting Lines
Updated on 2026-09-05
About this chapter
When two lines intersect, four angles are formed. Linear pairs add up to 180° and vertically opposite angles are equal. If all four angles at a crossing are equal, each is 90° and the lines are perpendicular . Parallel lines lie in the same plane and never meet, however far they are extended. They are marked with matching arrow heads. A transversal cutting two lines makes 8 angles, with at most 4 different sizes. Corresponding angles are equal exactly when the two lines are parallel — this is the test for parallelism. For a transversal across parallel lines: alternate angles are equal, and interior angles on the same side add up to 180°.
- Across the Line
- Perpendicular Lines
- Between Lines
- Parallel and Perpendicular Lines in Paper Folding
- Paper Folding, and Notations
- Sections 5.5 Transversals and 5.6 Corresponding Angles
- Corresponding Angles
- –119Section 5.7 Drawing Parallel Lines
- Drawing Parallel Lines
- Alternate Angles
Exercises
- In-text Questions — Across the Line Page 106
- In-text Questions — Across the Line Page 107
- Figure it Out — Across the Line Page 108
- In-text Questions — Perpendicular Lines Page 108
- In-text Questions — Between Lines Page 109
- In-text Questions — Between Lines Page 110
- Activity 2 — Parallel and Perpendicular Lines in Paper Folding Page 111
- In-text Questions — Paper Folding, and Notations Page 112
- –114Section 5.4 Parallel and Perpendicular Lines in Paper Folding — Figure it Out Page 113
- Sections 5.5 Transversals and 5.6 Corresponding Angles — In-text Questions Page 115
- Activity 3 — Corresponding Angles Page 116
- Activities 4 and 5 — Corresponding Angles Page 117
- –119Section 5.7 Drawing Parallel Lines — In-text Questions Page 118
- Figure it Out — Drawing Parallel Lines Page 119
- In-text Questions — Alternate Angles Page 120
- –122Section 5.8 Alternate Angles — Examples Page 120
- –125Section 5.8 Alternate Angles — Figure it Out Page 123
- In-text Questions — Parallel Illusions Page 125