2 concentric circles have their area in ratio 4:9 and the radius of the inner circle is 7cm. What is the diameter of the outer circle?
Answers
Answered by
10
Answer:
Let AI is the area of the inner circle
A2 is the area of the outer circle
thenAi:A2 = 4:9
Area of inner circle πr 2 = 22x7^2/r=I54cm2
4:9=154: A2
A2 = 9x154/4=I386/4=346.5cm2
πR2=346.5
R2 = 346.5x7/22=110.25
R =v110.25=10.5
diameter of outer circle=lo.5x2
= 21cm
Answered by
1
Answer:
10.5 cm
Step-by-step explanation:
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