Question

if angle COB : angle OBC = 2:1, AD is parallel to BC, then the value of angle a is​

Answer 1

Answer:

90

Step-by-step explanation:

COB //OBC =2:1=2x:x

AD //BC =2:1=2x:x

2x+x+2x+x=180

6x=180

x=180/6=30

2x=60

Value of a =2x+x

3x

3*30=90 Ans

Answer 2

Answer:  Step-by-step explanation: angle A + angle O = angle a (exterior angle is equal to sum                                                                                                                of two opposite anles)  30°+ 90°= a° 120°= a°