WAEC Mathematics 2010 Paper

Concept:The sum of exterior angles is always $360^\circ$, and the sum of interior angles is $(n-2) \times 180^\circ$.Explanation:For any convex polygon, the sum of exterior angles is constant: $360^\circ$.The sum of interior angles of an $n$-sided polygon is $(n-2) \times 180^\circ$.Given that the exterior angle sum is half the interior angle sum, we write:$360^\circ = \frac{1}{2} \times (n-2) \times 180^\circ$Simplify the right-hand side:$360^\circ = (n-2) \times 90^\circ$Divide both sides by $90^\circ$:$4 = n-2$So, $n = 4 + 2 = 6$.Answer:$n = 6$ (Option A).