The radius of the circle was reduced by 4 times. How did the following change: a) the circumference; b) the area of the circle?

a) l = 2piR;
l1 = 2piR / 4 = piR / 2;
2piR> piR / 2 by 4 times, therefore, the circumference decreased by 4 times.
b) S = piR ^ 2;
S1 = pi (R / 4) ^ 2 = piR ^ 2/16;
piR ^ 2> piR ^ 2/16 16 times, it follows that if the radius is reduced 4 times, then the area of the circle will decrease 16 times.



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