If the area of the triangle is 8, we use 1/2bh to find it. Since b and h are the same on this triangle, we find that 8=1/2(4)(4)
Now we know that the two sides of the parallelogram and the top two sides of the triangle are all 4. We just need to find the bottom of the parallelogram to know the perimeter. It’s the same as the hypotenuse of the right triangle.