Dissemble means to conceal your thought or feeling. I figured out my definition because I know that dis mean "not" and semble means to seem. So if you attach the words together it is "not seem." This proves that the word dissemble means to conceal or hide your thoughts.
Answer: This equation has 2 solutions, namely x = ±√400 = +20 or -20
The negative solution does not make sense because a length cannot be less than 0.
The total length needed to go around the painting is the perimeter of the square, which is
P = 4*x = 4*20 = 80 inches