JAMB Mathematics 2021 Paper

Concept:The area of a trapezium is half the product of the sum of the parallel sides and the perpendicular distance between them.Explanation:Let the distance between the parallel sides be $h$.The parallel sides are $5\text{ cm}$ and $9\text{ cm}$, so their sum is $14\text{ cm}$.Area formula:$$\text{Area} = \frac{1}{2}(\text{sum of parallel sides}) \times h$$Substitute the area and the side lengths:$$91 = \frac{1}{2}(5 + 9)h$$Simplify the bracket:$$91 = \frac{1}{2} \times 14 \times h$$$$91 = 7h$$Divide both sides by $7$:$$h = \frac{91}{7} = 13$$Therefore, the distance between the parallel sides is $13\text{ cm}$.Answer:A. 13 cm