9514 1404 393
Answer:
not a right triangle
Explanation:
These lengths will form a triangle iff ...
10 + 20 > 30 . . . . . false
These side lengths do not form a triangle. It is NOT a right triangle.
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Additional comment
We notice the differences between these numbers are the same: 10. The only right triangle with side lengths having the same difference is some multiple of a 3-4-5 right triangle. For a right triangle with side lengths having a difference of 10, the sides would have to be 30, 40, 50--not 10, 20, 30.