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

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
= 1.1²1
= 21%