GEO004 · Geometry basics · Classes 6–10
Angle Relationships
When a transversal cuts two parallel lines, corresponding and alternate angles are equal and co-interior angles add to 180°.
Angle Relationships📐 Formula
Corresponding = θ; alternate interior = θ; co-interior = 180° − θ; vertically opposite = θ
✏️ Worked example
θ = 60°: alternate 60°, co-interior 120°.
🌍 Where it is used
Railway tracks, ladders and road crossings.
❓ Quick check
Co-interior angles on parallel lines add up to…