Lines and Angles Practice
Solve chapter-level practice questions for Lines and Angles with reveal-only solutions and quick revision support.
Practice Set 1 — Angles at a Point and on a Line
Linear pairs, vertically opposite angles, complementary and supplementary angles.
Self-checked progress is stored in this browser, not synced to an account.
Practice Set 2 — Parallel Lines and Triangles
Transversal angle relations and the angle sum / exterior angle of a triangle.
Self-checked progress is stored in this browser, not synced to an account.
Quick Q&A Before You Revise
What is the difference between a linear pair and supplementary angles?
All linear pairs are supplementary (sum 180°) and are also adjacent, formed by a ray standing on a line. But two angles can be supplementary without being adjacent or forming a straight line.
Are vertically opposite angles always equal?
Yes. Whenever two straight lines intersect, each pair of vertically opposite angles is equal. This is a proved result, not an axiom.
How can the angle relations be used to prove two lines are parallel?
If a transversal makes a pair of equal corresponding angles, or equal alternate angles, or co-interior angles adding to 180°, then the two lines cut by it are parallel.
Why is an exterior angle of a triangle equal to the sum of the two interior opposite angles?
The exterior angle and its adjacent interior angle form a linear pair (sum 180°), and the three interior angles also sum to 180°. Subtracting the common interior angle gives the exterior angle equal to the sum of the other two interior angles.