Angles made between the radius and the tangent to a circle is a right angle. This is illustrated in the schematic below:
We now use Pythagoras to solve for AB where we have a right angle of AB as adjacent, 6 and 10 as opposite and hypothenuse respectively.
Hypothenuse, h is given as
[tex]a\text{ = }\sqrt[]{h^2-o^2}[/tex][tex]undefined[/tex]
