Question

$\overleftrightarrow{AB}$ and $\overleftrightarrow{CD}$ intersects each other at point $O$. Measure of one angle formed by intersection is ${120}^{\circ }$, then the measure of another three angles are ${60}^{\circ }$,${120}^{\circ }$,${60}^{\circ }$.

• A. True
• B. False

Answer 1

The correct option is A True

Given $\angle 1={120}^o$.

Then, $\angle 3=\angle 1={120}^o$........[vertically opposite angle]

Also $\angle 1+\angle 2={180}^o$........[linear pairs]

$⟹\angle 2={180}^o-{120}^o={60}^o$

Again $\angle 4=\angle 2={60}^0$........[vertically opposite angle]

Hence other three angles are ${60}^o,{120}^o$ and ${60}^o.$

So given statement is true.