Question

ans this pls i will mark brainliest

Answer 1

i think answer is 120
OBA = 30 ...... 1
OAB = 30 ( linear pair ) ........ 2
1 + 2 = 30 + 30 = 60
sum of triangle = 180
180 - 60 = 120
Hence problem is proved

Answer 2

ANSWER:
120°

EXPLANATION:

Given:
/_OBA = 30°

To find : /_APB

°•° OA and OB are the radii of same circle
•°• OA = OB
°•°∆OAB is an iscoles traingle

/_OBA = /_OAB(angle opposite to equal sides)

•°•/_OAB = /_OBA = 30°

In ∆ OAB
/_OAB + /_OBA + /_AOB = 180°(Angle sum property)
30° + 30° + /_AOB = 180°
/_AOB = 180° - 60°
/_ AOB = 120°

Now,
/_O + /_AOB = 360° [Angle sum ]
/_O = 360° - 120°
/_O = 240°

°•° The angle subtended by an arc at the centre is double the angle of subtended by it at any point on the remaining part of the circle

•°• 2/_APB = /_O
/_APB = 240° ÷ 2
/_APB = 120°