from a rectangular chart paper of size 100cm by 80cm ,six squares of side 20cmwere cut out .find the area of the remaining chart paper please answer!!

Length of rectangle = 100cm ; 

Breadth of rectangle =  80 cm ;

Side of the square = 20 cm ;

 Area of a rectangular chart paper = 100 * 80 = 8000 sq. cm

 Area of a square piece cut from the chart paper = 20 * 20 = 400 sq. cm

 Area of 6 square pieces cut from the chart paper = 400 * 6 = 2400 sq. cm.

 Area of remaining chart paper = 8000 - 2400 = 5600 sq. cm.