1. Area of Circles with Exercises Geometry Regular Program SY 2014-2015 Sources: Discovering Geometry (2008) by Michael Serra Geometry (2007) by Ron Larson

2. CIRCUMFERENCE vs. AREA Imagine a string that will be wrapped around a coin, or wheel (without overlaps). The length of that string determines the circumference of the circular object. In any circle, the ratio Circumference over diameter is constant. This ratio is known as pi. Pi is equal to 3.14159265359…

3. How do we get the area of a circle? A circle can be separated into smaller parts that resemble a “pizza slice”.

4. How do we get the area of a circle? A circle can be separated into smaller parts that resemble a “pizza slice”.

5. How do we get the area of a circle? Rearrange the pieces to form a “paralellogram”. Half of circumference

6. Area of Circles and Parts

10. Example: Area of Circles and Parts

11. Example: Area of Circles and Parts

12. Example: Area of Circles and Parts

13. Half of circumference Determine the area of the shaded region.

20. Determine the area of the shaded region made up of semicircles.

21. Determine the area of the shaded region. The arcs are from a circle with radius of 6cm. The quadrilateral is a square.

22. Which shaded region has a greater area?

23. Determine the area of the shaded region.