how to construct angle of 150?pls justify
We are in 9th, so you should be knowing to bisect an angle, right?
Draw a 180 degree (line).(QR)
On it, construct 120 degrees (60 + 60) ..... (PT)
Bisect the angle between 180 and 120 degrees.
The bisecting ray (PU) and 0 degree (PR) will form your 150 degree angle
VERIFYING: 180 - 60 = 120
Half of 60 = 30
Therefore angle UPR = 120 + half of 60
= 120 + 30 = 150
Hope i could help!