AB is a chord of a circle with centre o such that AB is 16cm and the radius of circle is 10cm tangents A and B intersect each other at p find the length ofPA
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here two things must be known.
first that OP is perpendicular to AB (since a line through centre bisects the chord perpendicularly.)
second radius is perpendicular to tangent .
thus OA is perpendicular to AP.
cos (OAL)=AL/OA=8/10=4/5
we know that cos(37)=4/5
thus angle OAL=37
therefore angle LAP = 90-37=63 degrees
cos(LAP)=AL/AP
>3/5=8/AP
>AP=40/3
first that OP is perpendicular to AB (since a line through centre bisects the chord perpendicularly.)
second radius is perpendicular to tangent .
thus OA is perpendicular to AP.
cos (OAL)=AL/OA=8/10=4/5
we know that cos(37)=4/5
thus angle OAL=37
therefore angle LAP = 90-37=63 degrees
cos(LAP)=AL/AP
>3/5=8/AP
>AP=40/3
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