Workshop: Angles and Lines

Partners Follow Directions to Draw Angles and Lines. Have all pairs take out a sheet of blank, unlined paper and rulers.

In this activity, partners take turns asking each other to draw or identify a geometric figure on the paper. Issue the first direction to all: draw a line and label it . Subsequent directions will be issued by one of the partners and should involve additions to the initial line, such as the following:

• Draw a line that intersects and makes at least one acute angle. Label the new line .
• Draw a line that is perpendicular to .
• Draw a line parallel to .
• Draw a ray that intersects and does not make right angles.
• Draw a ray that intersects and is perpendicular to .
• Draw a line parallel to .
• Outline a triangle that has been made by the lines already drawn.
• Name an obtuse angle using three letters.

Figure 2 shows a possible result of the challenges above. With each addition, the partners check to see if they agree that the addition follows the directive correctly. Disagreements can be referred to a neighboring pair for resolution.