The distance between two points (D) is given by distance formula as
D=√(x2−x1)2+(y2−y1)2
(i) D =√(4−2)2+(1−3)2=√4+4=2√2 units
(ii) D =√(−5+1)2+(7−3)2=√16+16=4√2 units
(iii) D =√(a+a)2+(b+b)2=2√a2+b2 units