Circle radius calculation

The area of the two circles is in a 4:9 ratio. The larger circle has a diameter of 18 cm. Calculate the radius of the smaller circle.

Final Answer:

r1 =  6 cm

Step-by-step explanation:

D2=18 cm r2=D2/2=18/2=9 cm  S2=π r22=3.1416 92254.469 cm2  S1:S2 = 4:9  S1=S2 94=254.469 94113.0973 cm2  r1=S1/π=113.0973/3.1416=6 cm



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algebraarithmeticplanimetrybasic operations and conceptsGrade of the word problem

 
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