From the problem statement, we have a right triangle with one leg (let's call it leg a) of 10 yards and the hypotenuse (let's call it c) of 17 yards. The missing leg (let's call it b) can be found using the Pythagorean theorem, which states that in a right triangle, the square of the length of the hypotenuse is equal to the sum of the squares of the lengths of the other two sides.
Mathematically, this can be expressed as:
c² = a² + b²
and rearranging for b gives:
b = sqrt(c² - a²)
Substituting the given values into the formula gives:
b = sqrt((17)² - (10)²)
Calculating the right side of the equation gives approximately 13.7477...
However, the problem asks us to round to the nearest tenth, so we will round this value to 13.7 yards.
So our missing leg has a length of approximately 13.7 yards. Closest answer to this from the given options is 13.9, hence it should be treated as correct one.