Answer
a) 30 squares
b) The areas are: $16\ in^2$, $9\ in^2$, $4\ in^2$ and $1\ in^2$.
c) Area Addition Postulate
Work Step by Step
a) Count to find that there are 30 squares.
b) There are 4 red squares. Count the small squares, which are each 1 in, to find the dimensions of each square and compute the area.
$A_1=s^2=4^2=16$
$A_2=s^2=3^2=9$
$A_3=s^2=2^2=4$
$A_4=s^2=1^2=1$
c) Sum the results in part b.
$A=A_1+A_2+A_3+A_4=16+9+4+1=30$
The equality of the two results supports the Area Addition Postulate.
