A cuboid measures cm by cm by cm. What is the length of the longest diagonal inside it?
Answer and explanation
Correct answer: A. 13 cm
- Step 1: Use the three-dimensional form of Pythagoras: .
- Step 2: , so cm.
Answer
13 cm.
Why not the others: 19 cm: This adds the three edge lengths. 12.6 cm: This is the diagonal of the by face only. 5 cm: This is the diagonal of the by face only.
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