The area of a rectangular rug is given by the trinomial r squared minus 4 r minus 77r2−4r−77. What are the possible dimensions of the​ rug? Use factoring.

r2-4r-77 = (r-11)(r+7)
r has to be greater than 11 in order for the formula to represent the area of a rug since a side length cannot be less than or equal to 0.