Question

Acute angle between two lines is ${40}^{\circ }$. Find the obtuse angle between the same lines.

Answer 1

Acute angle between two lines + Obtuse angle between two lines$={180}^{\circ }$

${40}^{\circ }$ + Obtuse angle between two lines$={180}^{\circ }$

Obtuse angle between two lines$={180}^{\circ }-{40}^{\circ }={140}^{\circ }$

Obtuse angle between two lines$={140}^{\circ }$