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Question 84

A circle has a radius of 7 centimetres, and π is to be taken as exactly 3.14. Select all the statements that are true about the distance right round this circle.

  1. It is 153.86 centimetres.
  2. It is 43.96 centimetres.Bonne réponse
  3. It is found by multiplying 3.14 by 14, the full width of the circle.Bonne réponse
  4. It is 21.98 centimetres, from multiplying 3.14 by 7.

Explication

Doubling the 7 gives a width of 14, and 3.14 lots of that width measure the way round the edge. The value 153.86 counts the surface enclosed, which comes from squaring the radius first, and a surface can never be quoted in plain centimetres.

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Question 84: A circle has a radius of 7 centimetres, and π is to be… · Geometry Basics · Questena