Sheila is climbing on a ladder that is attached against the side of a jungle gym wall. she is 4 feet off the ground and is 3 feet from the base of the ladder, which is 18 feet from the wall. how high up the wall is the top of the ladder?

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