Will give brainliest

Me find the missing dimension of a triangle height: 7 in., area: 21^2

Determine the relationship of ab and cd given the following points

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