Alright first get the sector formula which is
(3.14)(r)^2(measure of the degrees / 360) now plug it in the formula
(3.14)(8.91)^2(81/360)
3.14 x 79.4 x 81 = 20,194.596/360 = 56.1 cm squared and that I believe should be the answer to that :)
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