Question

The area of an isosceles trapezium is 34 $c{m}^2$ and the length of one of the parallel sides is 10 $cm$ and height is 4 $cm$. Find the length of the other parallel side.
(3 marks)

Answer 1

Let the length of the other parallel side be ${}^{\prime }{b}^{\prime }$
Length of one parallel side ($a$) = 10 am and height ($h$) = 4 cm
(0.5 marks)

Area of trapezium = $\frac{1}{2}(a+b)\times h$
$\Rightarrow 34=\frac{1}{2}(10+b)\times 4$
$\Rightarrow 34=(10+b)\times 2\Rightarrow 34=20+2b$
$\Rightarrow 34-20=2b\Rightarrow 14=2b$
$\Rightarrow 7=b\Rightarrow b=7$
(2 marks)

Hence, the other parallel sides is 7 cm.
(0.5 marks)