triangle, or (20) = 10 inches. The area of one sector of the circle is of the entire
circle, so the area of a sector is A = πr^2 = π(10)^2 = (100π) = π square inches.
Therefore, the total area of the three sectors is = 50π square inches. Now subtract
the area of the sectors from the area of the triangle: 100 − 50π ≈ 16, or (F). If you picked
(H), you may have subtracted the area of only one of the sectors.
60 . J The total degrees in any n-sided polygon is given by the equation (n − 2)·180°. You use this
equation to figure out that for an octagon, the total number of degrees is (8 − 2)·180° =
6·180° = 1,080°. Divide the total number of degrees by 8 to find the measure of each interior
angle: = 135°. If you picked any of the other answers, you may have been using an
incorrect value for the total degrees in the octagon.
