What is "in circle c?

"In circle" refers to a circle that is inscribed within a polygon, meaning that the circle is tangent to all sides of the polygon. This means that the circle is contained within the boundaries of the polygon and does not extend beyond them.

The in circle of a polygon is also known as the incircle, and it is the largest circle that can fit inside the polygon without crossing any of its sides.

The center of the in circle is called the incenter, and it is the point where the angle bisectors of the polygon intersect. The radius of the in circle is called the inradius, and it is the distance from the center of the circle to any of its points.

The in circle of a polygon is useful in geometry for various calculations, such as finding the area or the perimeter of the polygon. It is also useful in architecture and engineering for designing structures with inscribed circles.