When a rectangular sheet of metal is heated its length and breath increase by 10 percent Calculate the overall percentage increase in area?

Answer 1

21%

Area = length*width

Let Aoriginal represent the original area and Aheated represent the area of the rectangle after heating. Let l and w represent the original length and width of the rectangle. Because l and w increase by 10% on heating, we have the following:

Aheated = (1.10*l)(1.1*w)=1.21(l*w)

Because Aoriginal = l*w,

Aheated =1.21(l*w)=1.21*Aoriginal

So the area of the rectangle increases by 21% upon heating.