Geometry and reasoning
Build and connect the representations and methods in geometry and reasoning.
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Before you begin
Build and connect the representations and methods in geometry and reasoning.
Learning goals
- Construct a geometric argument or proof
- Reason about congruence, similarity and scale factors
Syllabus statements covered
- properties of parallel lines cut by a transversal, perpendicular and angle bisectors, triangles, special quadrilaterals and circles • congruent and similar triangles • midpoint theorem • tangent-chord theorem (alternate segment theorem) (The first two properties are learnt in G3 Mathematics.)
- properties of parallel lines cut by a transversal, perpendicular and angle bisectors, triangles, special quadrilaterals and circles
- congruent and similar triangles
- midpoint theorem
- tangent-chord theorem (alternate segment theorem)
In this topic
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Midpoint and tangent–chord proofs
Derive midpoint relationships, distinguish alternate segments and build a non-circular proof with a missing-condition counterexample.