AB=(4+1)2+(0+1)2​=26​BC=(3+1)2+(5+1)2​=52​CA=(4−3)2+(0−5)2​=26​ In isosceles triangle side AB=CA For right angled triangle, BC2=AB2+AC2 So, here BC=52​ or BC2=52 or (26​)2+(26​)2=52 So, the given triangle is right angled and also isosceles.