Question

please mention the steps also ​

Answer 1

OAB = 60°

ACB = 90°

Given

angle AOB = 90°

and

angle ABC = 30°

In triangle AOB

angle AOB = 90°

angle ABO = 30°

•°• angle OAB = 180° - (90°+30°)

= 180° - 120°

= 60° ----------》1

In triangle ACB

angle CAB = 60° ( from 1 )

angle CBA = 30°

angle ACB = 180° - ( 60°+30°)

= 180° - ( 90°)

= 90°