Question

What is the number of arcs that need to be drawn during the construction of a 120-degree angle? __

Answer 1

A 120-degree angle is the double of the 60-degree angle. The steps for its construction are:

Step 1: Draw a line segment. Mark the left end as point O and the right end as point B.
Step 2: Take the compass and open it up to a convenient radius. Place its pointer at O and with the pencil-head make an arc which meets the line OB at say, P.
Step 3: Without disturbing the radius, place the pointer at P and make an arc that cuts the previous arc at a point, say Q.
Step 4: Similarly, with the same radius on the compass, place the pointer at point Q. Mark another arc on the first arc. Mark the point where they intersect as A.
Step 5: Draw a line from O through A.

Therefore, during the procedure of construction of a ${120}^{\circ }$ angle, 3 arcs are drawn.