Went over homework dealing with exterior angle theorem and triangle angle sum theorem. Took assessment on triangle congruence proofs, coordinate geometry, and transformations review. Started homework if we finished early.
Homework: p. 207: #6 parts a thru f. (CO-C10b)
Resources:
first 6 minutes are similar to homework: https://www.youtube.com/watch?v=wnqNC2wWdUo
basics of midsegments: https://www.youtube.com/watch?v=iR8fvqgY4NM
some more examples, not on coordinate plane: https://www.youtube.com/watch?v=MbITaIYqUk4
midsegment applet to play around with: http://mathopenref.com/trianglemidsegment.html
Passed back assessments and went over some helpful details about proofs. Then discussed some about the proof of the triangle midsegment theorem and worked through examples using it. Also defined the term median and centroid and looked at some examples of it. (CO-C10b) lecture notes linked HERE
Homework: p. 208: #9-11 p. 201 #8-11 (CO-C10b)
Resources:
some resources about proofs/congruence: http://mathopenref.com/tocs/congruencetoc.html
midsegment basics: https://www.youtube.com/watch?v=wslcvpXHaJA
triangle midsegment applet: http://mathopenref.com/trianglemidsegment.html
triangle median applet:: http://mathopenref.com/trianglemedians.html
triangle centroid applet: http://mathopenref.com/trianglecentroid.html
midsegment examples: helps with p 208: https://www.youtube.com/watch?v=KT3U9br3qk0
basics of centroid: https://www.youtube.com/watch?v=VGgD-BQZaXI
some numeric median/centroid examples: https://www.youtube.com/watch?v=s0ra2ar8zs8
coordinate centroid (#8 on p 201): https://www.youtube.com/watch?v=KNGDdXSBkVw
Went over homework on midsegments and centroids. Constructed the centroid of a triangle using the following worksheet/tasks: link here Then applied the special property of the midpoint to see how it is the center of mass. Watched this video to see what the center of mass really means. Then developed the Centroid formula for the coordinate plane. (Similar to this video). (CO-C10b)
Homework: p. 203-4 #1 and 2
Some hints for the homework: be sure to read the set-up for the problem, especially how each unit represents 20 feet of real-life length. Also, you will need to use the distance formula (or Pythagorean Theorem) quite a bit for this task. Also in part 2b, you can use the coordinate centroid formula we came up with in class; click here to see that formula.
Resources
See Tues/Wed post above for many help videos
centroid construction/balancing demonstration: https://www.youtube.com/watch?v=EdumukHLEfw
lots of centroid ratio examples: https://www.youtube.com/watch?v=BDjgd4ibep0