Shape and Space 9
2 marks · EasyExplain how to use Pythagoras’ theorem to calculate the direct distance from one corner of a cuboid to the opposite corner (the space diagonal).
Work this out on paper, then compare with the answer and worked solution below. With a free account you can submit written answers for marking.
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Must show: State all three sides are squared, Add the squares together, Take the square root
Also accept: First use 2D Pythagoras across the base, then use again for vertical height.
Common mistakes: Forgetting to include all three dimensions
Show mark scheme and worked solution
Marking points
M1 · 1 mark · States/uses that all three side lengths are squared and added
A1 · 1 mark · States that the square root of the sum gives the diagonal length
Worked solution
Square the length, width, and height of the cuboid, add the three squares together, then take the square root to find the space diagonal.