Answer:These lengths are that of a right triangle.
Explanation: The longest length for a right triangle is always the hypotenuse. So by applying Pythagoras
20 squared + 21 squared should give the same value as 29 squared
If this is not, then it is not a right triangle.
Consider 20 squared + 21 squared gives 841
Now compare this to 29 squared = 841
Conclusion: These lengths are that of a right triangle
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