The area of a circle is 38.5cm2. Find its diameter [take \(\pi = \frac{22}{7}\)]

  • A 22cm
  • B 14cm
  • C 7cm
  • D 6cm
waec 2000mathematics

The correct answer is C. 7cm

\(\pi r^2 = 38.5\\

\frac{}{} = r^2 = 38.5\\

r^2 = \frac{38.5 \times 7}{22}\\

r = \sqrt{12.25} = 3.5\\

diameter = 2r = 2 \times 3.5 = 7cm\)

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