The distance between points P(x1​,y1​,z1​) and P(x2​,y2​,z2​) is given byPQ=(x2​−x1​)2+(y2​−y1​)2+(z2​−z1​)2​ (i) Distance between points (2,3,5) and (4,3,1)=(4−2)2+(3−3)2+(1−5)2​ =(2)2+(0)2+(−4)2​ =4+16​ =20​ =25​ (ii) Distance between points (-3,7,2) and (2,4,-1)=(2+3)2+(4−7)2+(−1−2)2​ =(5)2+(−3)2+(−3)2​ =25+9+9​ =43​ (iii) Distance between points (-1,3,-4) and (1,-3,4)=(1+1)2+(−3−3)2+(4+4)2​ =(2)2+(−6)3+(8)2​ =4+36+64​=104​=226​ (iv) Distance between points (2,-1,3) and (-2,1,3)=(−2−2)2+(1+1)2+(3−3)2​ =(−4)2+(2)2+(0)2​ =16+4​ =20​ =25​