Which angles are adjacent to each other? Question is located in the attached file (image)

On a piece of paper graph f(x)=5•(0.4)^x

The area of a rectangle is 10 cm^2. one side of the rectangle is x cm. express the perimeter of the rectangle in terms of x and show that this rectangle cannot have a perimeter of 12 cm. the perimeter of the rectangle in terms of x is __ cm

Pls the last one and it has to be like number 6