Have students learn the difference between parallel, perpendicular and intersecting lines with this two- part lesson plan. First, draw sets of lines, which are either parallel, perpendicular or intersecting, on the board or on a worksheet. Students should explain or define what kind of graph it is. For the second part, write down pairs of slopes, which correspond to parallel, perpendicular or intersecting lines. Students should explain which slope belongs to which graph and why.
Use geometric shapes to learn the difference between perpendicular lines and intersecting lines. Cut out triangles, squares, rectangles, circles and other polygons. Have students select which shapes contain perpendicular lines and draw them in. Then have them look at remaining shapes and try to fold them to make perpendicular lines. You can also use rulers or straightedges to create shapes. Explain to students that any L-shape is perpendicular. Use a variety of rulers to create different geometric designs and have students define the line types.
Teach students how to find the point of intersection with this activity. On a graph, draw two line segments that are not touching. Explain that each line segment is just part of a longer line. Students should find the slope of each line segment and use that information to write the equation for each line, i.e., y=mx+b. Set the equations equal to each other and solve for the variables, to find the point of interception.
Get the whole class on their feet in this fun interactive group activity. Explain to students the differences between intersecting, parallel and perpendicular lines, by illustrating examples on the black board. Divide the class into small groups. Call out a line pair type, e.g., parallel lines. The students should then make a set of parallel lines. The first group to do so is the winner. For a one-on-one modification, have the student use his arms to show the different line relationships.