Draw an angle of . Copy its supplementary angle.
To construct an angle of measure and a copy of its supplementary angle listed below are the steps tat are to be followed
1. Draw a line segment PQ mark a point O on it. Place the centre of protractor at point O and the zero edge along line segment PQ.
2. Consider point O as centre, draw an arc of convenient radius in the interior of ∠POA. Let this intersects both rays of ∠POA at points B and C respectively.
3. Draw a line m and mark a point S on it. Again draw an arc by taking S as centre with the same radius as used before. Let it cut the line m at point T.
4. Now adjust the compasses up to the length of BC. Taking T as centre draw an arc with this radius which will intersect the previously drawn arc at point R.
5. Join RS. Here RS is the required ray which makes same angle with the line m, as the supplementary of [i.e. ]