Given cot A = 2/5 and that angle A is in Quadrant I, find the exact value of sin A in simplest radical form using a rational denominator.

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