<u>Given</u>:
The given triangle is a similar triangle.
The length of the hypotenuse is 18 units.
The length of the leg is a.
The length of the part of the hypotenuse is 16 units.
We need to determine the proportion used to find the value of a.
<u>Proportion to find the value of a:</u>
We shall find the proportion to determine the value of a using the geometric mean leg rule.
Applying the leg rule, we have;

Substituting the values of hypotenuse, leg and part, we get;

Thus, the proportion used to find the value of a is 
Hence, Option D is the correct answer.
Answer:
96
Step-by-step explanation:
Using side b as the base, 4 points makes 3 bases (the space in between). With three bases, you can have 3 bases of 1 segment, 2 bases of 2 segments, and 1 base of 3 segments. This equals 6 bases. Each of these can connect to a point on line a. 6x6=36
Using side a as the base, 6 points makes 5 bases. With 5 bases, you can have 5 bases of 1 segment, 4 bases of 2 segments, 3 bases of 3 segments, 2 bases of 4 segments, and 1 base of 5 segments. This equals 15 bases. Each of these can connect to a point on line b. 15x4=60
36+60=96
139,000,000 over 1, any number is a fraction just put it over 1