If d length n breath of a rectangle r increased by 10% then by wt %wiil the area increase?

Answer 1

If the shapes are similar, area increase as the square of the ratio of the lengths.

In this case, the shape remains the same,
so
old area = d*n
new area = (1.1d)(1.1n)
= (1.1)² dn
= (1.1)² old area
Percentage increase in area
= 1.1²-1
= 21%