9514 1404 393
Answer:
obtuse
Step-by-step explanation:
Using the idea of a "form factor", we find ...
f = a² + b² - c²
f = 25² +30² -50² = 625 +900 -2500 = -975
The form factor is negative, so the triangle is obtuse.
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Additional comment
The form factor, as defined above, classifies the triangle according to its sign:
f > 0 . . . acute
f = 0 . . . right
f < 0 . . . obtuse
The largest angle in the triangle can be found from ...
cos(C) = f/(2ab)
Here, it is C = arccos(-975/1500) ≈ 130.5416°
