Answer:
12x = perimeter , y^2 cm - 25 cm^2 = area of shaded area
Explanation:
The perimeter of a triangle is just adding up all the sides together.
since you need to leave it in terms of x, you would just add 5x+3x+4x
which equals 12x
The area of a square is one side times itself.
so the area of the large square is y x y which is y^2
to find the shaded area, you subtract the area of the large square by the area of the small square so:
(y x y)- 25 cm^2 or y^2-25 cm^2 = area of shaded area