Final answer:
The perimeter of a 30-60-90 triangle with a hypotenuse of 5 cm is calculated using the ratios specific to this type of triangle. The perimeter is the sum of all three sides, resulting in D)11.8 cm when rounded to the nearest tenth.
Step-by-step explanation:
The question asks for the perimeter of a 30-60-90 triangle with a hypotenuse of length 5 cm, rounded to the nearest tenth. In a 30-60-90 triangle, the sides are in the ratio 1:√3:2. Therefore, if the hypotenuse is 5 cm, the shorter leg (opposite the 30-degree angle) is half the hypotenuse, which is 2.5 cm, and the longer leg (opposite the 60-degree angle) is the shorter leg times √3, which is approximately 4.33 cm. To find the perimeter, we add up the lengths of all three sides.
Perimeter = shorter leg + longer leg + hypotenuse
= 2.5 cm + 4.33 cm + 5 cm
= 11.8 cm
Thus, the perimeter of the triangle rounded to the nearest tenth is 11.8 centimeters, which corresponds to option D.