Question

The shape of the cross section of a canal is a trapezium. If the canal is 10 m wide at the top, 6 m wide at the bottom and the area of its cross section is 640 m², find the depth of the canal.

Answer 1

 

Area of the trapezium=`1/2xx"(Sum of the parallel sides)"xx"(Distance between the parallel sides)"` 

⇒`640=1/2xx(10+6)xxh` 

⇒`1280/16=h` 

⇒`h=80m` 

Therefore, the depth of the canal is 80 m.