Common Core · Grade 8
8.EE.B.6
Grade 8 — Use similar triangles to explain slope, and derive y = mx + b for a line through the origin and elsewhere.
Grade 8 — Use similar triangles to explain why the slope is the same between any two points on a line, and derive the equation y = mx + b.
The 2 skills that cover it
- Linear FunctionsWork with straight lines: slope as a rate of change, intercepts, and the equation y = mx + b.Read the lesson →
- Forms of a LineWrite the equation of a line in point-slope, slope-intercept and standard form, convert between the three, read intercepts off standard form, and build parallel and perpendicular lines through a point.Read the lesson →
What a student should be able to do
- Compute the slope between two points.
- Write the equation of a line from a slope and a point.
- Interpret slope and intercept in a real-world context.
- Identify parallel and perpendicular slopes.
- Write the equation of a line from a point and a slope in point-slope form, and from two points.
- Convert between slope-intercept form y = mx + b and standard form Ax + By = C.
- Find both intercepts of a line given in standard form.
- Write the equation of the line through a point that is parallel or perpendicular to a given line.