Geometry of Straight Lines, 2D Shapes & Construction
Geometry of Straight Lines, 2D Shapes & Construction is one of 8 topics in the Grade 9 Mathematics CAPS syllabus, covered across 3 lessons on Study Vault. Below are real practice questions from this topic with full worked answers.
Sample practice questions
Easy
1. Two angles on a straight line are x and 115°. Find x.
Answer: 65 — Angles on a straight line sum to 180°: x+115=180, so x=65.
Easy
2. What is true of vertically opposite angles formed by two intersecting lines?
They are always equal
They always sum to 90°
They are always supplementary
They are never equal
Answer: They are always equal — Vertically opposite angles (formed in an X shape by two crossing lines) are always equal.
Medium
3. A transversal cuts two parallel lines. One angle is 70°, and its corresponding angle is y. Find y.
Answer: 70 — Corresponding angles are equal: y=70°.
