Slope of line l (m1)=5 Slope of line w(m2)=-1/5 Since,m1×m2=-1 , line 'l' and 'w' are perpendicular. Since line 'k' doesn't intersect line 'l' ,they must be parallel b'coz they are in the same plane as well. Here, 'l' is perpendicular to 'w' and parallel to 'k'....so w and k must be perpendicular to each other. It can be proven: Since l and k are parallel, their slopes are equal. So, slope of k (m3)=5 Since m3×m2=-1 ,w and k are perpendicular. Hence, angle between w and k is 90°
According to the Exterior Angle Theorem, the exterior angle is equal to the sum of the interior angles opposite from the exterior angle. In other words:
