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.

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

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?

Circumference

The distance around a circleCircumference = 2 π r

DiameterA 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)(r2)

d a C c/d c/a a/d

d=diametera= areac= circumference

Which ratios, if any, seem invariant as you change the size of the circle?

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