Question

The cross-section of a canal is a trapezium 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.

Answer 1

Given that,

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

Area = 72 m2

Let the distance between parallel sides of trapezium = x meter

We know that,

Area of trapezium = 1/2 ( Sum of lengths of parallel sides) × distance between parallel sides

i.e., Area of trapezium = 1/2 ( Sum of sides) × distance between parallel sides

72 = 1/2 (10 + 6) × x

72 = 8 × x

x = 72/8 = 9

∴ The depth is 9m.