Question

find the radius of a circle whose circumference is 3.9cm

Answer 1

your answer is 1.95....

Answer 2

Here is your answer.....
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We know that

circumference of circle = 2πr

Given ,

circumference of circle = 3.9 cm

2πr = 3.9



$r = \frac{3.9}{2\pi} \\ \\ r = \frac{39 \times 7}{10 \times 2 \times 22} \\ \\ r = \frac{273}{440} \\ \\ r = 0.62 \: cm$
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Hope this helps you......