8th Grade Math District Formative Assessment-Extended Response Name______________________________________! Date__________________________________ Teacher_____________________________________ ER.DFA2.8.M.EE.06 Use similar triangles to explain why the slope (m) is the same between any two distinct points on a non-vertical line in the coordinate plane; derive the equation y = mx for a line through the origin and the equation y = mx + b for a line intercepting the vertical axis at b. 1. Which statement below is false concerning the triangles in the graph? a. The triangle’s slope remains constant. b. The rise and run of each triangle are proportional. c. The triangle’s do not have the same slope. d. The slope of the line is -2. 2. Which of the following statements is false concerning the graph below? ! ! ! ! a. The triangles are proportionate to each other. b. The slope of the smaller triangle is 2; the slope of the larger triangle is 4 c. The rise and run of the smaller triangle is - 2/2. d. The rise and run of the larger triangle is - 4/4. 3. Are the points (-4,8), (0,2), and (2,-1) collinear? a. no, because they do not lie on the same line. b. yes, because they have a positive slope. c. no, because the first point is farther from the second point than the third point. d. yes, because they have the same slope ratio. 4. Using the figure below, write the slope-intercept equation for lines Revised 11/8/13! © Vail School District 8th Grade Math District Formative Assessment-Extended Response Name______________________________________! Date__________________________________ Teacher_____________________________________ 5. On the coordinate plane below, sketch the graphs of the following linear equations: ! a) y = 3x ! b) y = 3x + 1 ! c) y = 3x − 1 Explain the relationship between the lines by identifying what they do and don’t have in common. Revised 11/8/13! © Vail School District 8th Grade Math District Formative Assessment-Extended Response Name______________________________________! Date__________________________________ Teacher_____________________________________ AK.ER.DFA2.8.M.EE.06 Use similar triangles to explain why the slope (m) is the same between any two distinct points on a non-vertical line in the coordinate plane; derive the equation y = mx for a line through the origin and the equation y = mx + b for a line intercepting the vertical axis at b. 1. Which statement below is false concerning the triangles in the graph? a. The triangle’s slope remains constant. b. The rise and run of each triangle are proportional. c. The triangle’s do not have the same slope. d. The slope of the line is -2. 2. Which of the following statements is false concerning the graph below? ! ! ! ! a. The triangles are proportionate to each other. b. The slope of the smaller triangle is 2; the slope of the larger triangle is 4 c. The rise and run of the smaller triangle is - 2/2. d. The rise and run of the larger triangle is - 4/4. 3. Are the points (-4,8), (0,2), and (2,-1) collinear? a. no, because they do not lie on the same line. b. yes, because they have a positive slope. c. no, because the first point is farther from the second point than the third point. d. yes, because they have the same slope ratio. 4. Using the figure below, write the slope-intercept equation for lines Revised 11/8/13! © Vail School District 8th Grade Math District Formative Assessment-Extended Response Name______________________________________! Date__________________________________ Teacher_____________________________________ 5. On the coordinate plane below, sketch the graphs of the following linear equations: ! a) y = 3x ! b) y = 3x + 4 ! c) y = 3x − 4 Explain the relationship between the lines by identifying what they do and don’t have in common. b) a) c) The lines have equivalent slopes and have different y-intercepts. Revised 11/8/13! © Vail School District