we have that
a=(-6,11) b=(2,8) c=(-1,0)
step 1
find the distances with the formula
d=√[(y2-y1)²+(x2-x1)²]
distance ab
dab=√[(8-11)²+(2+6)²]----> dab=√73 units
distance bc
dbc=√[(0-8)²+(-1-2)²]----> bc=√73 units
distance ac
dac=√[(0-11)²+(-1+6)²]----> dac=√146 units
the legs are
ab=√73 units
bc=√73 units
the hypotenuse is
ac=√146 units
the sum of the squares of the lengths of the legs is
(√73)²+(√73)²=73+73-----> 146
the answer is
146