The radius of a semicircle increases by 20%. What would be the change in its parimeter
Answers
Answer:
20% perimeter will decrease
Step-by-step explanation:
formula to calculate perimeter of a semicircle is 1/2*(pi*d)+d
when we decrease the value of radius by 20 % the value of diameter will decrease by 20 % .
using formula for example diameter of semicircle is 1 so we put it in equation
1/2*(3.14*(1/2))+1/2 = 1.285
now decrease the diameter by 20 % it will be
1* 20/100=0.2
new diameter will be 1-0.2 = 0.8
so put it again in the equation
1/2(3.14*(0.8/2))+0.8/2=1.028
so not we will check the percentage again
(1.028/1.285) *100= 80%
so the behavior will be liner. if we change the radius it will change the perimeter with the same ratio
Answer:
The perimeter of the semicircle increases.
Step-by-step explanation:
The perimeter of semi circle is calculated by using the following formula: pi*r+d, r is the radius and d is the diameter. Suppose the radius is 10 m , then the perimeter is , pi*10 +20=51.41 m. Now after increasing the radius by 20 percent the new value of r is 1,2*10 =12 m. By putting 12 in place of 10 we get 61.69 m. Now subtract the initial perimeter value from the new one , we will get 61.69-51.41=10.28.
% increase= [(difference between the initial and final value of perimeter)/initial value] * 100)
= 10.28 *100/51.41 = 19,99 which is almost 20 percent.