Answer: No
Explanation:
Using the Converse of the Pythagorean Theorem which is in square length of the longest side is equal to sum of the square lengths of the other to sides, then the triangle is a right triangle.
So, you make an equation were the longest side (18 in this problem) equals the other two sides (9 and 12).
So the equation would look like:
18^2=9^2+12^2
Then you would solve for each number squared and end up with:
324=81+144
Solve:
324=225
Since the equation is false this is not a right triangle, but according to the obtuse triangle inequality theorem which is if the square length of the longest side is greater than the square length of the other side sides then the triangle is an obtuse triangle. So, this triangle is not a right triangle but an obtuse triangle.
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