The window shown here is a composite of a rectangle and a semicircle. if each square of the grid is six inches by six inches, what is the perimeter of the rectangular part of the window, abcd? include only the outside perimeter.

132 inches

Step-by-step explanation:

We need to find the perimeter of the rectangular part of the window, ABCD include only the outside perimeter. It means that we need to know the length of sides AD, DC and BC only and then the perimeter is the sum of those 3 sides.

Given that:

A square of the grid is six inches by six inches

=> AD or BC = 8 * 6 inches = 48 inches long  

From point D to point C, there are 6 square in horizontal

=> DC =  6 * 6 inches = 36 inches long  

=> the perimeter of the rectangular part of the window, ABCD which include only the outside perimeter is:

AD+ DC +BC = 48 + 36 + 48 = 132 inches