Question 1180243
the center of the dartbord is at (0,0).
the diameter is 18 inches, which means the radius is 9 inches.
the formula for a circle is (x-h)^2 + (y-k)^2 = r^2
(x-h) is the x-coordinate of the center of the cirvle.
(y-k) is the y-coordinate of the center of the circle.
r is the radius.


that formula becomes (x-0)^2 + (y-0)^2 = 9^2


the graph of the circle looks like this:


if the dart lands on (6 7), then the distance from the center of the circle is sqrt((6^2 + 7^2) = sqrt(85) which is greater than wqrt(81).
this means the dart has not landed on the dartboard.


here's what the graph looks like.


<img src = "http://theo.x10hosting.com/2021/051202.jpg">