C. 5/2.
You can get the scale factor by putting the measurements of similar sides on a fraction,
In this case 20/8 =5/2, 10/4 = 5/2
A is the approximate distance
Answer:
5
Step-by-step explanation:

<u>Formula</u>
<em>An expression that uses variables to state a rule is a </em><u><em>formula</em></u>
<h2>
Explanation:</h2>
An expression that uses variables to state a rule is a formula. It's important to know that formulas uses the equals sign (=) and includes two or more variables. Formulas gives us information that we express symbolically. For example, the well known formula for the volume of a sphere is defined as:

So in this formula we have a relationship between the volume of a sphere and its radius, so if we have information about the radius of it we can easily calculate the volume of it.
<h2>Learn more:</h2>
Volume of prism: brainly.com/question/12501166
#LearnWithBrainly
<u>The answer is 808/99</u>