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.

الشرح

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.