YES, this is correct. All quadrilaterals whether is a trapezoid, parallelogram, rhombus and others, they are all polygons and all they have 4 sides and 4 angles. We know that a polygon is a figure with at least three sides and three angles.
Not all polygons are quadrilateral, this is also correct since some polygons have five or more sides and angles.
So, let's make these two values improper fractions so they're easier to work with. 
So, to get the rate he grew in those months we have:
And to get the rate he grew in one month we have to divide both our numerator and our denominator by 21 to get:
aka he grew 1.24 inches in a month.
Answer:
35.71
Step-by-step explanation:
Divide 269.50 by 14 and the answer is the average cost per visit