We can break this complicated looking shape into two more familiar ones, an icosoles triangle and a rectangle. Using the area of a triangle formula (base*height)/ 2, we get (3*6)/2=18/2= 9. Next, we multiply 8 by 16 to solve for the rectangle and get 128. We add 9 and 128 to get 137.
The cost on startup is $10 and each painted rock cost around $0.75 to make. A store pays startup cost and buy painted rocks for $0.75 each there no profit because the cost price and selling price is the same.