Question

construct an angle of a. 120 digree with the help of ruler and compass

Answer 1

Firstly draw an line segment and lab as AB
Now take any measure and make semicircle from point A
And lab as CD
Now cut an arc from point C of same measure
Now again cut an arc from first arc
Now join second arc from point A
Finally lab the construct diagram.

Answer 2

I can show you the construction
sorry for the explanation.....