Paul Dawkins
Paul's Online Notes: Algebra: Lines
Detailed math tutorial features notes and examples that discuss graphing lines and introduces the concept of slope, the standard form of the line, the point-slope form, slope-intercept form, and parallel and perpendicular lines.
Illustrative Mathematics
Illustrative Mathematics: G Gpe Equal Area Triangles on the Same Base Ii
This task has students apply their knowledge of parallel lines to solve a geometric problem on areas of triangles. The task is open-ended in that students can choose their method of completing the task. Aligns with G-GPE.B.5.
University of North Carolina
University of North Carolina Wilmington: Lines in a Plane
This site from the University of North Caroline at Wilmington provides great information on the lines in a plane. The information that is given is in-depth and complete, touching on the slope of a line, equations of lines, and linear...
Math Open Reference
Math Open Reference: Intersection of Two Straight Lines
Learn about the intersection of two straight lines with this helpful reference tool. Provides a detailed definition, examples, and an interactive activity that enhance further explanation. Includes links to related topics.
Illustrative Mathematics
Illustrative Mathematics: G Gpe a Midpoint Miracle
In this task, students are asked to draw a quadrilateral so that no two sides are congruent, no two angles are congruent, and no two sides are parallel. The task gives students the opportunity to prove that if we join the midpoints of a...
Illustrative Mathematics
Illustrative Mathematics: G Gpe, G Co, G Srt Unit Squares and Triangles
In this task, students are shown three unit squares and two line segments connecting two pairs of vertices. They are asked to find the area of a triangle formed by intersecting lines. They can solve it using coordinate geometry or...