Consider an area of cross-section of canal as ABCD.

Area of cross-section = 6 × 1.5 = 9 m^{2}

Speed of water = 10 km/h = 10000/60 meter/min

Volume of water that flows in 1 minute from canal

= 9 x 10000/60 = 1500 m^{3}

Volume of water that flows in 30 minutes from canal

= 30 × 1500 = 45000 m^{3}

^{}

Let the irrigated area be A. Volume of water irrigating the required area will be equal to the volume of water that flowed in 30 minutes from the canal.

Vol. of water flowing in 30 minutes from canal = Vol. of water irrigating the reqd.

45000 =(A x 8)/100

A = 562500 m^{2}