Use math/way it can help u a lot forget the /
That 2 means we multiply 4 by itself 2 times, and -4 x -4 = positive 16.
~Deceptiøn
160% of 19 is 30.4
Convert 160 into a decimal: 160%/100 = 1.6
Multiply the decimal by 19: 1.6 × 19 = 30.4 <-- our answer.
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0.9% of 54 is 0.486
Convert 0.9% in a decimal: 0.9%/100 = 0.009
Multiply the decimal by 54: 0.009 × 54 = 0.486 <-- our answer.
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15% of 376 is 56.4
Convert the percentage into a decimal: 15%/100 = 0.15
Multiply the decimal by 376: 0.15 × 376 = 56.4 <-- our answer.
Hello,
The formula for finding the area of a circular region is:

then:

With the two radius it is formed an isosceles triangle, so, we must obtain its area, but first we obtain the height and the base.

Now we can find its area:
![A_{2}=2* \frac{b*h}{2} \\ \\ A_{2}= [r*sen(40)][r*cos(40)]\\ \\A_{2}= r^{2}*sen(40)*cos(40)](https://tex.z-dn.net/?f=A_%7B2%7D%3D2%2A%20%5Cfrac%7Bb%2Ah%7D%7B2%7D%20%20%5C%5C%20%20%5C%5C%20A_%7B2%7D%3D%20%5Br%2Asen%2840%29%5D%5Br%2Acos%2840%29%5D%5C%5C%20%20%5C%5CA_%7B2%7D%3D%20r%5E%7B2%7D%2Asen%2840%29%2Acos%2840%29)
The subtraction of the two areas is 100cm^2, then:
Answer: r= 1.59cm