π
∞
∑
∫
θ
E = mc²
y = mx+b
√
Δ
φ
∇
λ
About this video
Grade 8 Mathematics Paper 2, November 2023 (Eastern Cape) worked through: geometry terms, angle pairs on parallel lines, triangles and congruency, the Theorem of Pythagoras and quadrilaterals — with a reason for every step.
What it covers
- Terms: transversal, supplementary, scalene, vertex, rhombus
- Vertically opposite (X), corresponding (F) and alternate (Z) angles
- Angles on a straight line and in a triangle
- Congruency: SSS, SAS and AAS
- The Theorem of Pythagoras, only in a right-angled triangle
- Kites, and the angles of a quadrilateral
Extra worked examples
✍️ Extra example: a right-angled triangle has shorter sides of 9 cm and 12 cm. Find the hypotenuse.
- 1c² = 9² + 12²The hypotenuse is opposite the right angle — and the theorem works ONLY in a right-angled triangle.
- 2c² = 81 + 144 = 225Square, then add.
- 3c = √225 = 15 cmThe inverse of squaring is the square root.
✍️ Extra example: three angles on a straight line are 90°, 4x + 6° and 2x. Find x.
- 190° + (4x + 6°) + 2x = 180°∠s on a str line.
- 26x = 84° → x = 14°Like terms together, numbers to the other side, then divide.
Exercises to try
Work each one out, then click to reveal the answer.
- 1Two angles add up to 180°. What are they called?
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Supplementary angles (complementary angles add up to 90°) - 2Vertically opposite angles are 4x and 52°. Find x.
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4x = 52° (vert opp ∠s) → x = 13° - 3A right-angled triangle has a hypotenuse of 26 cm and one side of 10 cm. Find the other side.
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y² + 10² = 26² → y² = 676 − 100 = 576 → y = 24 cm - 4A quadrilateral has angles of 95°, 85°, 110° and x. Find x.
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x = 360° − 95° − 85° − 110° = 70° (∠s of a quad) - 5△ABC and △DEF have AB = DE, BC = EF and B̂ = Ê. Are they congruent? Give the condition.
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Yes — two sides and the angle between them: SAS
Practise this topic
Download matching Grade 8 papers and worksheets.
