WAEC Mathematics 2025 Paper

Concept:For a regular polygon, each exterior angle equals $\frac{360^\circ}{n}$, where $n$ is the number of sides. Hence, the angle must divide $360^\circ$ exactly.Explanation:Check each option by dividing $360^\circ$ by the given angle.For $95^\circ$: $\frac{360^\circ}{95^\circ}$ is not a whole number.For $78^\circ$: $\frac{360^\circ}{78^\circ}$ is not a whole number.For $72^\circ$: $\frac{360^\circ}{72^\circ} = 5$, which is a positive integer.For $85^\circ$: $\frac{360^\circ}{85^\circ}$ is not a whole number.Since only $72^\circ$ gives an integer value of $n$, it can be the exterior angle of a regular polygon.Answer:C. $72^\circ$