Let r = the distance from P(-2,-4) to Q(-4,-2);
r = √{(-4 - -2)² + (-2 - -4)²}
r = √{-2² + 2²}
r = √{4 + 4}
r = √8
Let q = the distance from P(-2,-4) to R(7,-1):
q = √{(7 - -2)² + (-1 - -4)²}
q = √{9² + 3²}
q = √{81 + 9}
q = √90
Let p = the distance from Q(-4,-2) to R(7,-1):
p = √{(7 - -4)² + (-1 - -2)²}
p = √{11² + 1²}
p = √{121 + 1)
p = √122
If PQR is a right triangle, then:
p² = q² + r²
122 = 90 + 8
122 ≠ 98
Therefore, it is not a right triangle.
