The vector wequalsaiplusbj is perpendicular to the line axplusbyequalsc and parallel to the line bxminusayequalsc. it is also true that the acute angle between intersecting lines that do not cross at right angles is the same as the angle determined by vectors that are either normal to the lines or parallel to the lines. use this information to find the acute angle between the lines below. 2 x plus 5 yequals3, 7 x plus 3 yequals6