Wednesday, December 19, 2007
Algebra (Class 38)
Lesson Title
Area Formulas of Polygons
Overview
In today’s class our we will take a quiz focusing on the work we have done on the “Plane Shapes” problems we have been working with over the last few weeks. In addition, we will continue our work with areas of polygons. In particular we will focus on the relationship between the area and side length of squares, learning about the square root operation, how to approximate the value of the square root of a number, when the square root of a number will be whole, when it is “irrational”, and when it is “imaginary”. We will also work towards memorizing the first 25 perfect squares and will see how thinking about area can help use with this task.
Textbook Sections
§9-1 (Txt. p.413) The Graphing Method
Vocabulary
irrational numbers
imaginary numbers
perfect squares
square roots
Key Attitudes
Math is about investigating and confirming
Key Ideas
The coordinates of the point of intersection of two lines is the solution to both equations simultaneously.
Equations can be used to verify the point of intersection by substituting and evaluating the equations. If both equations “work” with these values, then the point is the point of intersection of both lines-- otherwise it is not.
The length of the side of a square can be found by taking the square root of the area of the square.
Only “perfect squares” have whole number square roots.
Only positive numbers have square roots, but all numbers can be squared.
Key Skills
Writing and using equations of lines.
Parallel lines have equal slope.
Finding the area of a polygon using a formula.
Finding the perimeter of a polygon using a formula.
Turn-In (#37)
Turn in #37
Txt. p.653 #19, 20, 30-34, 60, 66
Packet through SP11
Plane Shapes 8
Handouts
No Handouts Posted
Assignment
Finish packet through SP17
Disclaimer- The assignment as stated in class is the official assignment. Every effort is made to keep this posting accurate, but you should refer to what was stated in class as the final word.
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