Which binomial must be added to (2r+12) so that the sum of two polynomials is (6r-7)?

14.4 square units

Step-by-step explanation:

Keep in mind that the area here is a fraction of the area of a full circle of radius 8.

(area of sector) = (fraction)(pi)(8)^2

The fraction is the given central angle (pi over 7) divided by 2pi:

       pi            1

    * = 1/14

     7             2pi

Multiply the formula     (fraction)(pi)(8)^2     found above by this fraction:

area of sector = (1/14)(pi)(8)^2  =  14.4 square units