8  Mohan wants to buy a trapezium shaped field. Its side along the river is parallel to and twice the side along the road. If the area of this field is 10500 m^{2} and the perpendicular distance between the two parallel sides is 100 m, find the length of the side along the river.


Answers (1)

Let the length of the side along road be x m.

Then according to question, lenght of side along river will be 2x m.

            Area \:of \:trapezium = \frac{1}{2}h(a+b)

So equation becomes :    

                         \frac{1}{2}100(x+2x) = 10500

or                              3x = 210

or                               x = 70

So the length of the side along the river is 2x = 140m.