math
posted by kaylee .
a rectangle has a base of 25 in. and a height of 15 in. if the shape is dilated with a scale factor of .6, what is the area of the new shape?

areas of similar shapes are proportional to the square of their sides
area of original
= (1/2)(25)(15) = 187.5
x/187.5 = .6^2/ 1
x = .36(187.5) = 67.5
or
new dimensions:
.6(25) = 15
.6(15) = 9
new area = (1/2)(15)(9) =67.5