Slide 1

Slide 2 Points on a Plane Coordinate Plane x y 1 2 3 4 5 6 7-7-6-5-4 -3-2 -1 76543217654321 -2 -3 -4 -5 -6 -7 Quadrant IQuadrant II Quadrant IIIQuadrant IV Coordinates are written as an ordered pair in the form (x,y). The x-coordinate is also called the abscissa and the y-coordinate is also called the ordinate. (2, 3) A B (-4, 6) C (-7, -5) D (5, -4) The coordinate plane works just like a number line. Slide 3 Graphing Polygons A polygon is a closed figure whose sides are line segments. The endpoints of the sides are called vertices. A polygon can be represented on a coordinate plane by locating its vertices and drawing the sides by connecting the vertices in order. -8 -6 -4 -2 2 4 6 8 8 6 4 2 -2 -4 -6 -8 Graph rectangle ABCD whose vertices are: A (8, 6), B (-8, 6), C (-8, -6), D (8, -6) A (8, 6) B (-8, 6) C (-8, -6) D (8, -6) We can find the dimensions of the rectangle by counting the number of units between the points. Find the length by subtracting the x-coordinates. (8) - (-8) = 16 Find the width by subtracting the y-coordinates. (6) - (-6) = 12 x y Slide 4 Area on the Coordinate Plane Lets take another look at that rectangle again. -8 -6 -4 -2 2 4 6 8 8 6 4 2 -2 -4 -6 -8 Graph rectangle ABCD whose vertices are: A (8, 6), B (-8, 6), C (-8, -6), D (8, -6) A (8, 6) B (-8, 6) C (-8, -6) D (8, -6) We already found the length and the width of the rectangle. Now we can use those measurements to find the area of the rectangle. The length = 16The width = 12 x y Slide 5 Triangle Area on the Coordinate Plane Graph the following points: A(4, 1), B(1, 5), C(-2, 1). Then connect the vertices and find the area of the polygon. -5 -4 -3 -2 -1 1 2 3 4 5 9 8 7 6 5 4 3 2 1 A (4, 1) B (1, 5) C (-2, 1) D (1, 1) Asi De Facil x y Slide 6 More Area Examples x y -5 -4 -3 -2 -1 1 2 3 4 5 5 4 3 2 1 -2 -3 -4 -5 (a)graph each polygon (b)identify the polygon (c) find the area. A (-3, -2), B (2, -2), C (2, 2), D (-3, 2) Example 1 (-3, -2) A (2, -2) B (2, 2) C (-3, -2) D length = 5width = 4 (a) (b)Rectangle (c) Example b A (-4, 2), B (0, 2), C (0, 7) -5 -4 -3 -2 -1 1 2 3 4 5 5 4 3 2 1 -2 -3 -4 -5 (a) (-4, 2) A (0, 2) B (0, 7) C (b)Right Triangle (c)base = 4height = 5 Example 3 A (-1, -1), B (3, -1), C (3, 3), D (-1, 3) -5 -4 -3 -2 -1 1 2 3 4 5 5 4 3 2 1 -2 -3 -4 -5 (a) (-1, -1) A (3, -1) B (3, 3) C (-1, 3) D (b)Square (c)side = 4 Slide 7 Graphing Homework Page 80 - 81 3 -19, 24, 25, 27 Do all problems on graph paper. Do all of number 3 on one grid, 4 15 on one grid, and 24, 25, and 27 each on separate grids