Angles made by the transversal - Theory

Chapter 5 Class 7 Lines and Angles
Concept wise

Corresponding angles have

• Different vertices
• Are on same side of transversal
• Have corresponding positions i.e. both upper left or lower left or upper right or lower right

So, corresponding angles are

• ∠ 1 and ∠ 5
• ∠ 2 and ∠ 6
• ∠ 3 and ∠ 7
• ∠ 4 and ∠ 8

For parallel lines,

corresponding angles are equal

Therefore,

∠1 = ∠5                                                                                                                                                    ∠2 = ∠6

∠3 = ∠7                                                                                                                         ∠4 = ∠8

To summarise,

 Type Angles Interior angles ∠3, ∠4, ∠5, ∠6 Exterior angles ∠1, ∠2, ∠7, ∠8 Pairs of Corresponding angles ∠1 and ∠5, ∠2 and ∠6, ∠3 and ∠7, ∠4 and ∠8 Pairs of Alternate interior angles ∠3 and ∠6, ∠4 and ∠5 Pairs of Alternate exterior angles ∠1 and ∠8, ∠2 and ∠7 Pairs of interior angles on the same side of the transversal ∠3 and ∠5, ∠4 and ∠6