Question

If the area of a trapezium is 28 cm² and one of its parallel sides is 6 cm, find the other parallel side if its altitude is 4 cm.

Answer 1

$$\begin{gathered} \text{Given:} \\ {\text{Area of the trapezium = 28 cm}}^2 \\ \mathrm{L}\text{ength of one of its parallel sides = 6 cm} \\ \text{Altitude = 4 cm} \\ \text{Let the other side be x cm.} \\ \text{Area of trapezium=}\frac{1}{2}\text{×(Sum of the parallel sides)×(Altitude)} \\ \Rightarrow \text{28=}\frac{1}{2}\text{×(6+x)×(4)} \\ \Rightarrow 28=2\times (6+\text{x)} \\ \Rightarrow \text{6+x=}\frac{28}{2}\text{=14} \\ \Rightarrow \text{x=14-6=8 cm} \\ \text{Hence, the length of the other parallel side of the trapezium is 8 cm.} \end{gathered}$$