So we need to find the area of the unshaded region. This is equal to the area of the right triangle minus that of the square. The area of a right triangle is given by the product of its legs divided by two. Then the area of the right triangle in question 9 is:
[tex]\frac{(5+8)\cdot9}{2}=\frac{13\cdot9}{2}=58.5[/tex]
The area of a square is given by the square of the length of its sides so the area of the shaded square is:
[tex]5\cdot5=25[/tex]
Then the area of the unshaded region is:
[tex]58.5-25=33.5[/tex]
Then the area is equal to 33.5 square centimeters. The notation requested by the question indicates that we have to express this number with a + or - symbol followed by 4 digits, a dot and then 2 digits. Then the answer is +0033.50.
