Took assessment on law of sines and cosines + review
Homework
Start studying these formulas: http://bit.ly/formulas18
Finished assessment if necessary. Started unit on area/volume/3D with a 3 act task related to two glasses of soda. Looked at what the meaning of π really is and used it to find the reason behind the circumference formula being C=2πr. Then looked at different methods for proving the area of a circle being πr^2 through subdividing a circle into little 'pizza slices' (sectors) or 'onion rings' (concentric circles) and rearranging to either a rectangle or a triangle with the base being part or all of the circumference. Made the connection that a cylinder is just a stack of circles so the volume is the circle area times the height of the stack. Closed with another 3 act task dealing with cylinders with the same surface area.
Notes from board
Homework
p. 475 #1-6, 11
Bring headphones for Thursday/Friday
Continue studying these formulas: http://bit.ly/formulas18
Animations and videos watched in class:
meaning of pi
circumference showing 2π radii
area of a circle by rearranged slices
video of area of a circle by rearranged slices
interactive area of a circle applet
circle area unraveled into triangle
circle intro triangle video
(Mr M was out on Thursday.) Passed back assessments, then went to computer lab to remediate on skills missed on the assessment. (Those video are available here.) Then took an EOC practice test on trig and review skills. Got last practice assessment for third quarter.
Homework
finish, then check the practice assessment: (blank copy) (SOLUTIONS)
assessment is Monday for 1B, Tuesday for 234A
Resources
Law of Sines to find a side: link
Law of Cosines to find a side, then Law of Sines to find an angle: link
Law of Cosines to find an angle: link
Pythagorean Theorem examples: link1 link2
Dilating figure around non-origin center: link1 link2
Finding scale factor of dilation not around origin: link1 link2
Finding missing sides of triangle, given similar pair: link1 link2 (starts at 5:45)