Question P6 Work backwards from volume or area
A square has area 100 cm². Write its side length using square-root notation, then evaluate it.
Answer
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Work backwards from volume or area
Use the known area or volume to find the missing measurement.
In this one. A square has equal sides. Its side length is the positive square root of its area; this is different from dividing the area by two.
The question gives a cuboid's volume with two dimensions and asks for the third, or gives the volume with one length and asks for a face area. A square's area given with its side asked for belongs here too.
Children divide the volume by a length lying inside the face they want, instead of the length that runs into it, and get the wrong kind of measurement.
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