She's wrong. If you have two squares, [tex]S_1[/tex] with side [tex]s_1[/tex] and [tex]S_2[/tex] with side [tex]s_2[/tex], it's not true that the sum of their areas is equivalent to the area of a square [tex]S_3[/tex] with side [tex]s_3=s_1+s_2[/tex].
So, there's no point in summing the two sides. Instead, you have to compute the areas of the two squares and then sum them up.
So, the area of the first square is [tex]2.7^2[/tex], and the area of the second square is [tex]3.3^2[/tex].
Add these two numbers and you'll get how many squared meters of carpet she'll need.
