Class 7 · Chapter 5
Parallel and Intersecting Lines
Angle properties formed by parallel lines and a transversal.
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Ganita Prakash · Class 7 Part 1 (2026-27)
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Detailed theory
Corresponding: same position at each intersection. Alternate interior: opposite sides of transversal, between lines. Co-interior: same side, between lines.
Key concepts & formulas
01
**Parallel lines** never meet; **intersecting lines** meet at one point.
02
A **transversal** cuts two lines and forms 8 angles.
03
Corresponding angles: equal (if parallel).
04
Alternate interior angles: equal (if parallel).
05
Co-interior (allied) angles: supplementary (if parallel).