Answer:
=AC or 7.8102=AC
Step-by-step explanation:
If we connect a line from point A to point C we create a triangle, and we can use pythagorean theorem to find this distance. So the line from point A to point C will be our hypotenuse and the other two distances will be out side lengths.

25+36=
61=
=AC or 7.8102=AC
Dividing 20 by 100 gives us 1%. so 0.2 × 3 = 0.6 so it take 3 0.2s to get to 0.6. meaning 0.6 is 3% of 20.
PEMDAS
Parenthesis
Exponents
Multiplication
Division
Addition
Subtraction