Radius is the distance between the center and any point on the circle. r=distance =√((x2-x1)² +(y2-y1)²) =√((5-(-3))²+(-7-(-1))²)=√(64+36)=√100 = 10 r=√100
Equation of the circle , where (h, k) coordinates of the center of the radius. (h,k)=(5,-7) (x-h)² +(y-k)² = r² (x-5)² +(y+7)² = (√100)² (x-5)² +(y+7)² = 100
