In the figure XY and X'Y' are two parallel tangents to a circle with centre O and another tangent AB with point of contact C interesting XY at A and X'Y' at B, what is the measure of ∠AOB

In Fig XY and X'Y' are two parallel tangents to a circle with centre O and another tangent AB with point of contact C intersecting XY and X'Y' at B , prove that angle AOB = 90^@

PQ and RS are two parallel tangents to a circle with centre O and another tangent AB wih point of contact C intersect PQ at A and RS at B. then find angle AOB

In Fig.10.13 , and and are two parallel tangents to a circle with centre O and another tangent AB with point of contact C intersecting contact C intersecting at B.Prove that /_AOB=90^(@)

l and m are two parallel tangents to a circle with centre O,touching the circle at A and B respectively.Another tangent at C intersects the line l at D and m at E.Prove that /_DOE=90^(@).

In figure, CP and CQ are tangents from an external point C to a circle with centre O. AB is another tangent which touches the circle at R. If CP = 11 cm and BR = 4 cm. Find the length of BC.

A tangent to y^(2)=5x is parallel to the line y=4x+1 .Then the point of contact is