Answer:
not right-angled
Step-by-step explanation:
An isosceles right triangle has side lengths in the ratios ...
1 : 1 : √2
The triangle given here has side lengths in the ratios ...
3 : 11 : 11
These are not the same, so the triangle cannot be a right triangle.
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Additional comment
There are several ways you can look at this to determine it is not a right triangle.
- side ratios, as above
- the longest side of a right triangle is longer than either of the other two sides
- no side of this triangle is a diameter of the circumcircle
