2019 · Q78
Two circles are drawn with the same centre. The circumference of the smaller circle is 44 cm and that of the bigger circle is double the smaller one. What is the area between these two circles?
Elementary MathematicsCircles
- A154 square cm
- B308 square cm
- C462 square cm
- D616 square cm
Explanation
2πr = 44 gives r = 7 cm; the bigger circumference 88 gives R = 14 cm. Area between = π(14^2 − 7^2) = 147π = 462 cm^2.