Mr M was out today. We worked on EOC review on a handout. Here are the videos to help you with the review handout (blank copy)
#1-2: Segment addition: link (starts at 1:40)
#3-4: Angle addition: link (starts at 0:50)
#5-8: Angles in Parallel Lines with Algebra: link1 link2
#9-12: Slope of line perpendicular to given line: link
#13-14: Graphing Linear Equations: link (hint: solve for y first)
#15-16: Equation of line through two points: link
#17-18: Equation of line through point, perp to line: link
#19-22: Finding angles, using isos and eq triangles: link
Homework: watch and take notes on THIS video: link
Warm-up was to find the diameter of a sphere with the same volume as a cone with given slant height and diameter. Gave some details about the EOC at the end of the month, then did 'the ticket task' involving area (volume) of a circle (or cylinder) with a hole on it (called an annulus) to find the number of tickets wrapped in a roll. Then looked at circles in the context of art, history, architecture, and human representations in religion/spirituality. Learned how to find sector area and arc length in degrees.
Notes from board
Homework
p. 475-6: #7-10 (here is a digital copy of page)
have these formulas memorized ASAP: http://bit.ly/formulas18
Resources
finding area of sector: link
finding arc length: link
Warm up was to find the area of a circle given the length and measure of an arc, and then find the area of the sector associated with the arc. Did the pizza coupon task, which compared the effect on area of changing the radius versus the central angle of a sector. Then did the ring-road task which compared two different routes around/through a circular neighborhood to see which was faster/shorter. Looked at the difference between arc length and measure, and used arc measure as the basis to introduce radians as a more mathematical alternative to degrees for measuring angles and curvature. In radians, a circle is not 360 but rather 2π and thus 180=π forms the basis of converting to/from degrees and radians.
Notes from board
Homework
#5-8 and 13-16 on this handout
have these formulas memorized ASAP: http://bit.ly/formulas18
next assessment is 4/19 or 4/20
Resources
what are radians: link
how to find exact arc length and sector area: link