A circle that passes through all of the vertices of a polygon is called a Circumcircle or Circumscribed circle.
The center of the circumcircle is called the circumcenter.
All triangles, rectangles, and regular polygons have circumcircles.
In the figure below, the circumcircle (in black) of the triangle ABC passes through all its vertices A, B, and C
A. Figure 1
B. Figure 2
C. Figure 3
D. Figure 4
Correct Answer: C
Step 1: A circle that passes through all of the vertices of a triangle is called circumcircle of a triangle.
Step 2: In Figure 3, the circle passes through all the vertices of the triangle ABC.
Step 3: So, Figure 3 is the circumcircle of the triangle.