geometry question

Let's divide the pentagon into shapes like this:

By SSS congruency, the two triangles at the top are congruent, and so they have the same area.

area of one of the triangles  =  (1/2)(base)(height)  =  (1/2)(8)(6)  =  24  sq inches

area of rectangle  =  (length)(width)  =  (12)(8)  =  96  sq inches

area of pentagon  =  area of rectangle + 2(area of one of the triangles)

area of pentagon  =  96 sq inches + 2(24 sq inches)

area of pentagon  =  96 sq inches + 48 sq inches

area of pentagon  =  144 sq inches