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The interior angle of a polygon are in A.P.The smallest angle is 94º and the commondifference is 7º. Find the number of sides ofthe polygon. |
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Answer» Answer: Number of sides=5 Step-by-step explanation: Let no of sides=X Now in AP a=94 d=7,n=x then sum of the AP =x/2(2*94 + (x-1)*7)=(2x-4)90 x(188+7x-7)=180(2x-4) x(7x+181)=360x-720 7x²+181x-360x+720=0 7x²+181x-360x+720=0 7x²-179x+720=0 x=( 179 ±√(32041-4*7*720)/14 =( 179 ±√32041-20160/14 =(179±√11881)/14 =(179±109)/14 x=179-109/14 or x=70/14=5 Hence x=5 Number of sides=5 ========================== for other value of x=179+109/14=288/14=20.57 this is not perfect no. so can not be no. of sides = |
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