Final answer:
To find the length of the altitude CD, we can use the property of similar triangles. By setting up the proportion CD/AD = DB/AB and solving for h, we find that the length of the altitude CD is 16/3. Therefore, the correct answer is 20.
Step-by-step explanation:
To find the length of the altitude CD, we can use the property of similar triangles. Since triangle ABC is a right triangle, the altitude CD will divide the hypotenuse AB into two segments, AD and DB. We know that AD = 4 and DB = 16. Let the length of CD be h. By using the property of similar triangles, we can set up the proportion:
CD/AD = DB/AB
Substituting the given values and h for CD, we get:
h/4 = 16/(4 + h)
Cross multiplying the proportion, we get:
4h = 16(4 + h)
Simplifying the equation, we have:
4h = 64 + 16h
12h = 64
h = 64/12
h = 16/3
Therefore, the length of the altitude CD is 16/3, which is equal to approximately 5.333. Therefore, the correct answer is 4) 20.