Generate and Apply Formula of Circumference

Pi (π)

By definition, π is the ratio of the circumference of a circle to its diameter.

The relationship between the circumference and diameter  of a circle 

Measure the circumference and diameter of circular objects. Find the ratio of circumference to diameter for each object.

Ratio Relationship of π=C/d  

                           Circumference. It is the distance around a circle.  Keywords: fencing, framing, edge, border.


                                              C = π d                        C = 2 π r

π (Pi) Could be 3.1416,   or 3.14,  or  22/7,   or 3 if it is an approximation.
Approximately 3 diameters equal to the circumference of the circle.

r          Radius is half of the diameter

d          Diameter equals to two radius (radii)             

                              Area of Circles
Area.  It is the surface space inside a figure.
Keywords:   Painting, cutting grass, putting tiles.


Area of a Circle

Area of a Semicircle


CI02       Circumference_I

AR05      Circle_Area_I

CI01       Circle Circumference and Area 1

CI03       Circle Circumference and Area 2

CI04       Find diameter given circumference

CI05       Find radius given area

CI06       Circle_Problems

CI07       Semicircle

Circle_W   Circle Vocabulary



 Review: Area, Perimeter, & Circumference. Garcia Book, Practice Exercises:



Area of Circles 1

Area of Circles 2

Area of Part Circle 1

Area of Part Circle 2

Area of Part Circle 3

Area of Part Circle 4

Area of Part Circle 5

Please help me to improve this website by reporting any mistakes.
I would be grateful to know about.