Question P6 Circles and curved boundaries
A semicircle has radius 14 cm. Find its full perimeter. Use π = .
Answer
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Find the space inside a circle shape or the distance around its boundary.
In this one. Perimeter includes every outside edge: the curved arc and the straight edge or edges. Taking a fraction of the circumference alone misses the straight boundary.
'Area' asks for square centimetres from the radius. 'Circumference' or 'perimeter' on a curved edge asks for plain centimetres from the diameter instead.
Children give a circumference answer in square units, or find a circle's area without squaring the radius first, mixing up the two kinds of measurement.
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