+704 A line and a circle intersect at $A$ and $B,$ as shown below. Find the distance between $A$ and $B$.
The circle is x^2 + y^2 = 20.
The line is y = -4.
+37159 x^2 + (-4)^2 = 20
x^2 + 16 = 20
x= +-2
so the points of intersection are (2,-4) and (-2,-4) the distance between these points is 4 units
