1. Warm ups 3-31-09 What is the estimated perimeter of the shape? 10 cm 5cm 10 cm C = π d 10 For both blue parts together!! They both form one whole circle!! + 20 P= Use 3.14 for pi!

2. Which formula could you use to determine the height of the triangle? 15 in h Area = 120 sq. in. A. B. C. D. 120 15 1 15h =240 15 Two correct answers

3. What is the Area that is not covered by the pupil? Iris Pupil 3 mm 5 mm

4. Area of circle notes Not the outer edge, the inside space Multiply or

5. MOST COMMON MISTAKE!! DO NOT DO THIS!!!! Question: the radius is 7 mm on a circle. What is the area? Student does: A = 3 x 7 x 7 = A = 3 x 14 = A = 52 WHAT IS THE MISTAKE??? http://illuminations.nctm.org/ActivityDetail.aspx?ID=6