The cross-section of a canal is a trapqzium in shape. If the canal is 10 m wide at the top 6 m wide at the bottom and the area of cross-section is 72 m2 determine its depth.

Length of parallel sides of trapezium = 10m and 6m


Distance between parallel sides of trapezium = x meter


Area of trapezium =


72 =



Therefore depth of river is 9m


11