Class 7 · Chapter 5

Lines and Angles

Complementary, supplementary, adjacent, linear pair, vertically opposite angles; parallel lines and transversal.

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Detailed theory

Complementary: sum

= 90^\circ

. Supplementary: sum

= 180^\circ

. Adjacent: share a vertex and one arm. Linear pair: adjacent + supplementary (form a straight line).

Key concepts & formulas

Complementary angles sum to

90^\circ

Supplementary angles sum to

180^\circ

Vertically opposite angles are equal.

Corresponding and alternate interior angles on parallel lines are equal.

Co-interior angles on parallel lines sum to

180^\circ