Draw an angle of 80^(@) with the help of protractor . Then, construct angles of (i) 40^(@) (ii) 160^(@) and (iii) 120^(@) .

Draw an angle of 80^(@) with the help of protractor . Then, construct

1.	Draw an angle of 80^(@) with the help of protractor . Then, construct angles of (i) 40^(@) (ii) 160^(@) and (iii) 120^(@) .
Answer» Solution :First, draw an angle of `80^(@)say angleQOA = 180^(@)` with the help of protractor. Now, use the the following steps to construct angles of `(i) 40^(@) (ii) 160^(@) and (III) 120^(@)` . (i) Taking O as centre and any radius an which INTERSECT `OA` at `E` and OQ at F . (ii) Taking E and F as centres and radius more than `(1)/(2)EF` draw arcs which intersect each other at `P`. (iii) Join `OP`. Thus, `anglePOA = 40^(@) [because40^(@)=(1)/(2)xx80^(@)]` (iv) Now, taking `F` as centre and radius equal to `EF` draw an arc which intersect previous arc obtained in step ii at `S` . (v)Join `OS`. Thus, `angleSOA = 160^(@) [because160^(@)=2xx80^(@)]` (VI) Taking `S` and `F` as centre and radius more than `(1)/(2)SF` draw arcs which intersect each other at `R.` , (vii) Join `OR`. Thus , `angleROA = angleROQ = 40^(@) + 80^(@) = 120^(@)`