Geometryhard · Past Paper
In the figure, O is the center. PA and PB are tangents. If angle AOB = 120 degrees, find angle OAB.
A30 degrees
B60 degrees
C90 degrees
D120 degrees
✓ Correct Answer: A — 30 degrees
Triangle OAB is isosceles (OA=OB). Angle OAB = (180 - 120) / 2 = 30 degrees.
Share this question
More from Geometry
- In a circle with center O, chords AB and CD are equal. If angle AOB = 70 degrees, what is angle COD?
- In a cyclic quadrilateral ABCD, if angle A - angle C = 60 degrees, find angle A.
- Find the length of the line segment whose endpoints are (a, 0) and (0, a).
- If the radius of a circle is 7 cm, what is its circumference?
- The angle subtended by an arc at the center of a circle is 80 degrees. What is the angle subtended by the same arc at any point on the remaining part of the circle?