STEP 2: Use a ruler to draw a line from the end of the line through the dot and label the angle 40°. TIP: you won't know the exact length of this new side yet so draw it a bit longer than you ...

Use a pen to draw a dot where the arcs meet directly above the original horizontal line. Use a ruler and pen to join the ends of the line to the dot – you now have a regular equilateral triangle.