Answer:
Angles
Step-by-step explanation:
A polygon is a shape, I don't think there are conversions since a polygon is not something you can measure. A population can be counted with normal numbers, 1,2,3... density is calculated with mass and volume, not radians and degrees.... yeah.
Angles are measured in radians and degrees, so it's angles.
Hi, there.
_____
"5 less than 4 times a number" 4x-5
"is the same as" =
"9 times the number" 9x
Putting the parts together,

Solving the two step equation


Divide both sides by -5

So the A answer checks.
Hope the answer - and explanation - made sense,
happy studying!!