Review of the Grade 8 topics
Review: the interior angles of a quadrilateral add up to 360°, and of an n-gon to (n − 2) · 180°. Areas: parallelogram S = a · h, triangle S = ½ a h, rhombus S = d₁ d₂ : 2, trapezoid S = (a + b) : 2 · h. In a right triangle c² = a² + b² (the Pythagorean theorem); the area from the three sides is found with Heron’s formula. In a circle an inscribed angle is half its arc, and one on a diameter is 90°; a tangent is perpendicular to the radius, and tangent segments from an outside point are equal. A vector is determined by modulus and direction, sums use the triangle or parallelogram rule, and operations in coordinates act on corresponding coordinates.
“Year quiz”: in teams, write one question on each chapter (quadrilaterals, area, Pythagoras, circle, vectors) and pass it to another team.