Question

Question 5 (d)

Construct with ruler and compasses, angles of following measures:
${120}^{\circ }$

Answer 1

Steps of construction:

(i) Draw a ray $\overline{OA}$
(ii) Taking O as centre and convenient radius, mark an arc, which intersects $\overline{OA}$ at P.
(iii) Taking P as centre and same radius, cut previous arc at Q.
(iv) Taking Q as centre and same radius cut the arc at S.
(v) Join OS and extend it to point D. Thus,$\angle AOD$ is the required angle of ${120}^{\circ }$.