1. Bell Ringer What is the height of triangle FGH if the area is 45cm2 and the base is 10 cm? Please grab your calculators on your way into the room and start on the Bell Ringer.

2. b. Measure of angle CDE + EDF + EFD = 180 degrees c. Measure of angle EFD is less than measure of angle AED and Measure of angle FED is less than measure of angle BFD

3. Because we have two parallel lines that are a fixed distance apart, we know that our height is constant. If we are moving point D, we know that our base is always constant. Both our base and height never change, thus our area is invariant. Area = ½(BXH) Why is the area of triangle DEF invariant?

4. Circumference The distance around a circle Circumference = 2 π r Diameter A chord that passes through the center of a circle Ratio (of a to b) A comparison of a number a and a nonzero number b using division. a/b Area of circle Area of circle = (π)(r 2 )

5. daCc/dc/aa/d d=diameter a= area c= circumference Which ratios, if any, seem invariant as you change the size of the circle?

7. Write your summary. Pg. 56 #8,11a, 11b, 11c