Final answer:
Using the ratio of the sides in a 30°-60°-90° triangle, the longer leg is calculated to be 15 inches when the hypotenuse is 10\sqrt{3} inches.
Step-by-step explanation:
In a 30°-60°-90° triangle, the lengths of the sides have a specific ratio.
The hypotenuse (the longest side opposite the 90-degree angle) is twice as long as the shorter leg (the side opposite the 30-degree angle), and the longer leg (the side opposite the 60-degree angle) is \(\sqrt{3}\) times as long as the shorter leg.
If the hypotenuse is 10\sqrt{3} inches long, then the shorter leg would be half that length, which is 5\sqrt{3} inches long.
To find the measure of the longer leg, you multiply the shorter leg by \(\sqrt{3}\), which gives you 5\sqrt{3} \(\times\) \(\sqrt{3}\) = 15 inches.
So the measure of the longer leg is 15 inches, which corresponds to option C.