Here a photo of the answer. The first thing you have to do is split the figure into separate shapes. Find the area of the shapes, then add them all together.
Let's assume the number be x.
So, sum of a number and 10 can be written as x+10.
Now the given statement is "One half of the sum of a number and 10 ".
So, one half of x+10 can be written as 
-3.2b + 9
by adding like terms together.