Answer:
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Step-by-step explanation:
If a triangle is a right triangle, it can satisfy Pythagorean Theorem.

where a and b are the legs and c is the hypotenuse.
12 and 84 are the legs because are they shortest. 85 is the hypotenuse because it is the longest side.

Substitute the values into the formula.

Solve the exponents.
- 12²= 12*12=144
- 84²=84*84=7056
- 85²= 85*85=7225

Add on the right side.

7220 is not equal to 7225, so these sides cannot be a right triangle.