Can you construct parallel lines using a right triangle? Join Mrs. LaFont in constructing parallel line segments on a rectangular grid using different sized right triangles. We will also practice identifying parallel lines. For this lesson, you will need a pencil, a straightedge, scissors, blank paper, Lesson 13 Template 1 and Template 2 and the lessonâs Problem Set. You can access the Problem Set and the lessonâs template using the link below the video.