Geometry Math problem

[Guest]

What is the area in square centimeters of the shaded part of the rectangle?

[Guest]

The shaded area is a trapezoid with two "bases" of lengths 14 and 6 centimeters and height 10 centimeters. The area of such a trapezoid is the "average" of the two bases, (14+ 6)/2= 10 centimeters, and the height, 10 centimeters. The area is 100 square centimeters.

[Guest]

The area of shaded part to area of the rectangle minus area of triangle. Area of the rectangle is 140cm squared from 10cm (width) *14cm (length). Area of the triangle is 1/2*(14cm-8cm)*10cm= 40cmsquared.
Therefore the area of the shaded part is 140cmsquared-40cmsquared=100 cm squared