Explanation
In a right triangle, the sine of an angle x is given by the quotient between its opposite side and the hypotenuse. In this case, the horizontal distance between Michael and the basketball rim, the height of the rim and the ramp form a right triangle. The opposite side to the 20° angle is the height of the rim (i.e. the 10 ft side) whereas the hypotenuse is the ramp r. Then the sine of this angle is given by:
[tex]\sin20^{\circ}=\frac{10}{r}[/tex]Answer
Then the answer is option A.
