Divide a Line

Construction: Fig. 1.17

1. Draw a 100 mm long straight line AB.
2. Draw a line AC at any convenient acute angle with AB.
3. Set the divider to a convenient length and mark off seven spaces on AC. Let the points obtained be 1′, 2′, 3′, 4′, 5′, 6′, and 7′.
4. Join 7′ to the point B.
5. Draw lines through points 1′, 2′, 3′, 4′, 5′ and 6′ parallel to 7′B to meet AB at points 1, 2, 3, 4, 5 and 6 respectively. These points divide AB in equal length.

Bisect an Angle

1. Draw angle AOB of 75°.
2. Set the needle point of the compass at O, draw an arc CD of arbitrary radius to strike OA and OB at points C and D respectively.
3. With the ends C and D as centres, draw arcs of equal radius to intersect each other at the point P.
4. Draw a line from O through P. The line OP bisects the angle AOB.

Divide a Circle

Construction: Fig. 1.19

1. Draw a 50 mm diameter circle having O as the centre.
2. Using Drafter, draw diameters AG and DJ perpendicular to each other.
3. Draw arc of radius equal to the radius of the circle (= 25 mm) and A as the centre to meet the circumference of the circles at point C and K.