Michael X. answered 10/31/23
Veteran Tutor for Bio/Chem/Math; SAT/ACT/College App Advising
Recall the distance formula btn two points (x1, y1), (x2, y2) - d=√(x2 – x1)² + (y2 – y1)²)
Apply this formula to each pair of coordinates - (1,1), (1,3), and (5,2)
(1,1), (1,3) - d = √(1-1)2+(3-1)2 = 2
(1,1), (5,2) - d = √(5-1)2+(2-1)2 = √17
(1,3), (5,2) - d = √(5-1)2+(2-3)2 = √17
Since two of the sides have equal lengths, the triangle is isosceles.
The side lengths do not satisfy the Pythagorean theorem, so the triangle is not right.
Thus, the correct answer is - the triangle is isosceles, not right.
Happy to tutor you on any other questions you may have -- please feel free to shoot me a message!

Mark M.
Plotting the three points reveals an isosceles triangle. No arithmetic/algebra needed.10/31/23