Gave out unit calendar and announced unit project for extra credit, due May 4. That is also the date of our next test. Calendar and project info here. Continued discovering and proving theorems involving circles, including the indirect proof that a radius is perpendicular to a tangent line at the point of tangency. Similar proof here:
Homework: same as assigned Thurs/Fri of last week: p. 752: 11-27. See Last week's post for video help and textbook PDF files.
Tuesday/Wednesday
Warm up to launch class involving radius and tangents. Went over homework. Introduced idea of chord perpendicular bisector through discovery problem. Then discussed what an arc is, how to show notation for arcs, the difference between arc measure and arc length, and how to find arc measure based on the central angle using a pie chart. White board notes here. Then went through the formal proof for chord/radius perpendicular bisection.
Homework: p. 761-2: 19-35, 44-49
Textbook pages: 761 762
Resources:
Arc measure applet
Finding arc measure video ; chord and radius length video
Thursday/Friday
Homework from last night was collected after going over any troublesome problems. Opened with an exploration task involving making a circle from three non-collinear points. Here is the method. Then reviewed the previous concepts learned about circles and then discovered the reasoning behind the formulas for Arc Length and Sector Area. Then found the area of a circular segment by finding sector area and subtracting out the isosceles triangle's area. Notes from white board
Homework: p. 767: 12-22
Resources:
Arc Length
Sector Area
Circular Segment
Sector area and arc length examples; circular segment ex 1 ; circular segment example 2