Question

A circle has a diameter that starts

Answer 1

Find the distance between those points

diameter/2=radius


distance betwen (x1,y1) and (x2,y2) is
$D= \sqrt{(x2-x1)^2+(y2-y1)^2}$

given
(3,7) and (7,3)

$D= \sqrt{(7-3)^2+(3-7)^2}$
$D= \sqrt{(4)^2+(-4)^2}$
$D= \sqrt{16+16}$
$D= \sqrt{32}$
D=4√2

diameter/2=(4√2)/2=2√2

radius is 2√2