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Вопрос 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.Правильный ответ
  3. It is found by multiplying 3.14 by 14, the full width of the circle.Правильный ответ
  4. It is 21.98 centimetres, from multiplying 3.14 by 7.

Объяснение

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