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# to draw a pair of tangents to a circle which are inclined to each other at an angle of 100o it is required to draw tangents at end points of those two radii of the circle, the angle between which should be??

Asked by Shilpa Das , on 20/2/12

PA and PB are tangents drawn from an external point P to the circle.

âˆ OAP = âˆ OBP = 90Â°         (Radius is perpendicular to the tangent at point of contact)

âˆ APB + âˆ OAD + âˆ AOD + âˆ OBP = 360Â°

âˆ´ 100Â° + 90Â° + âˆ AOB + 90Â° = 360Â°

â‡’ 280Â° + âˆ AOB = 360Â°

â‡’ âˆ AOB = 360Â° â€“ 280Â° = 80Â°

Thus, the angle between the two radius, OA and OB is 80Â°.

Posted by Lalit Mehraon 21/2/12

This conversation is already closed by Expert

the angle between the two radius will be 80 degree . its is so because the tangents meet at 90 degree and the angles are inclined at 100 degree so adding 100 degree + 90 degree + 90 degree + the angle between the radii ( say x) = 360 degree  so the value of x is 80 degree.

Posted by Prachi Patelon 20/2/12

can u xplain me with a figure..

Posted by Shilpa Dason 20/2/12