Question

hi guys answer it fast it's urgent

Answer 1

it can be constructed by using = 60+1/2(60+30)

Draw a line AB and mark point O on it where angle is to be drawn.
With O as center draw an arc (semicircle) which intersects the line AB at points H and I.
Keeping the same radius as above and H as center, draw an arc which intersects the semicircle at point C. Without changing the radius as above and C as center, draw an arc which intersects the semicircle at point D. (The points C and D correspond to 60 and 120 degrees angle respectively).
Now draw two arcs of same radius keeping the centers as C and D respectively which intersect at point E.
Join points E and O and extend it to point X.
We get the angle XOB=90 degree.
Join the points O and D and extend it to point Y, so we get angle YOB=120 degree.
Angle YOX=Angle YOB-Angle XOB=120-90=30 degree
Now let’s bisect the angle YOX.
Draw two arcs of same radius keeping the centers D and F (point of intersection of EO and semicircle) which intersect at point G. Join GO.
We get the angle GOB=105 degree.

Answer 2

Here are steps:-
1) Draw a line AB
2) Take point M on AB as centre of circle
3) Draw a circle of any radius as M is centre which intersect AB on N
4) Make an arc as centre N

Draw an angle of 90° and 120°
Hence, 105 = 1/2(90+120)
Refer to attachment respectively:)