Go to   Fun_Math Content Table   Trisecting an Angle

#### 1. Ceva's Pantograph

Tomasso Ceva (1648 - 1737) published trisecting tool named "Ceva's Pantograph" in 1695.
Ceva's Pantograph is shown in the figure shown below.

Angle to be trisected is AOB.

Point O is a fixed point,and point P moves along the line PO.

PR = PS = RO = SO. Points R & S moves along the circle.

Trisection of the angle AOB is done when the line extending PR passes through

the point "A".

You can see the process in animation.

For detail, go to the section Ceva's Pantograph.
*********** pantograph_desc.dwg ***********

The principle used for Amadori's Link is the same as the one applied for Ceva's Pantograph decribed above. The straight edge is attached to a base plate which has a cutout circle. The point P of the stright edge moves along the bisector of the angle AOB while point R moves along the diameter of the circle. The trisection is accomplished when the line PR passes through point C.

You can see the process in animation.

One of the Laisant's Link is shown in the figure shown below.

You can see the process in animation.

For detail, go to the section Laisant's Links.
*********** Laisant_desc.dwg ***********

Kempe, Alfred Bray (1849 - 1922) published a very unique linkage used for angle trisection in 1875.
Kempe's Link is shown in the figure shown below.

You can see the process in animation.

For detail, go to the section Kempe's Links.

Sylvester,James Joseph (1814 - 1897) announced a linkage trisector,which he named "A Lady's Fan" ,in 1875.
Sylvester's Link is shown in the figure shown below.

You can see the process in animation.

For detail, go to the section Sylvester's Isoklinostat.

#### 6. Line Motion Trisector

Line Motion Trisector is shown in the figure shown below.

You can see the process in animation.

For detail, go to the section Line Motion Trisector.