19^2 + x^2 = 21^2
19^2 = 361
21^2= 441
361 + x^2 = 441
x^2 = 441-361 = 80
x = sqrt(80) = 8.944 round to nearest tenth = 8.9
Answer:

Step-by-step explanation:
<u>Equation of a Circle</u>
A circle of radius r and centered on the point (h,k) can be expressed by the equation

We are given the equation of a circle as

Note we have corrected it by adding the square to the y. Simplify by 3

Complete squares and rearrange:



We can see that, if r=4, then

Or, equivalently

There are two solutions for
:

Keeping the positive solution, as required:

Preserved the size because 12inchs is = to 1 ft.
2 rows of geraniums and 4rows of the other one