The radius is 10, so the diameter is 20. This means the parts of the diameter (the chord through the center P) to the left and right of the vertical chord have lengths 16 and 4, respectively.
Because the horizontal chord is a diameter, the vertical chord is cut in half, so its parts above and below the diameter both have length <em>x</em>.
Now, by the intersecting chord theorem,
16×4 = <em>x</em> × <em>x</em>
or
<em>x</em> ² = 64
so that
<em>x</em> = 8
Okay, so whatever the answer is to angle A its the same answer to angle C and angle B and D. the angle looks like a obtuse which means it has to be bigger than 90 degrees. use your protractor to measure it.
A zero in front of the x would make this a difference of two perfect squares. All of the other option would interfere by adding another term.
The answer is C 200
Because 10 / 200 = 0.05 * 100 = 5%
I hope this helps :)
