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
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