State the property that is used in each of the following statements: (i) If a||b, then ∠1 = ∠5. (ii) If ∠4 = ∠6, then a||b.(iii) If ∠4 + ∠5 + 180°, then a||b.

(i) Given, a||b, then ∠1 = ∠5 [Corresponding angles]
If two parallel lines are cut by a transversal, each pair of corresponding
angles are equal in measure.
(ii) Given, ∠4 = ∠6, then a||b [Alternate interior angles]
When a transversal cuts two lines such that pairs of alternate interior
angles are equal, the lines have to be parallel.
(iii) Given, ∠4 + ∠5 = 180°, then a||b [Co-interior Angles]
When a transversal cuts two lines, such that pairs of interior angles on the
same side of transversal are supplementary, the lines have to be parallel.

Class 7 Maths Chapter 5 Exercise 5.2

for more answers vist to:
https://www.tiwariacademy.com/ncert-solutions/class-7/maths/chapter-5/