Circle in Quadrilateral

Topic:
Circle

Constructing circles within quadrilaterals

The four green points are the vertices of a quadrilateral. The orange, blue and yellow points can be moved, changing the shape of the quadrilateral. The quadrilateral usually contains a circle touching all four of its sides. Explore and take note of your observations ... Source: https://pdst.ie/sites/default/files/S%26S%20manual_22.11.13.pdf, page 157.