Shade the top side of the boundary line if you have the inequality symbols > or ≥. Shade the bottom side of the boundary line if you have the inequality symbols < or ≤.

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Answer:
10 < x < 20
Step-by-step explanation:
the sum of any two sides of a triangle has to be greater than the 3rd side, so the maximum value of the third side in this instance is 19.9999999 because 10 + 10 = 20
The way to get the equation for the radius (r) is to get r by itself. So divide each side by 4pi
500/4pi=r^2
Now take the square root of each side to get the equation of r.
sqrt(500/4pi)=r