Properties of triangle and circles connected with them

Properties of triangle and circles connected with them
Circum circle : The point of intersection of perpendicular bisectors of the sides of a triangle ABC is called circum center. Then SA=SB=SC=R (let)  with center ‘s radius R passes through the vertices is called circum circle

note : 1) In an acute angled triangle  circum centre lies inside the circle
    2) ‘s’ lies outside the obtused angled
    3) In a right angled triangle circum centre(s) is the midpoint of hypotenuse
    4) In right angled triangle hypotenuse  is diameter of the circle