All you have to do is find the square root of 441 the square root of 441 is 21 the formula for Area is LxW so 21x21=441 The length of one side 21 square feet
In the parenthesis, 7 + c cannot be simplified, so there is no need for them. Now we have 7 + c + 4. Only 7 and 4 can be added. 7 + 4 = 11. The answer is 11 + c.