Section 4.1 Measuring and Layout Tools 65
Octagons
An octagon has eight equal sides, and all the
angles between the sides are equal. A stop sign
is a common example of an octagon. In wood-
working, you might fi nd an octagon shape in
furniture, such as a table with an octagonal top.
Follow these steps to lay out an octagon.
1. Refer to the design to fi nd the distance
across the octagon from one side to the
other.
2. Lay out a square using that dimension. This
is the distance A in Figure 4-20. Remember,
a square has four equal sides.
3. Using large dividers or trammel points, set
the size to half the diagonal of the square.
4. Place one point of the dividers or trammel
points at one corner of the square and strike
an arc from one side of the square to the
other.
5. Follow this procedure for all four corners.
The arcs are shown as dashed lines on
Figure 4-20.
6. Now join the points where the arcs meet
the sides of the square. Making these
connections will form the octagon.
Hexagons
A hexagon has six equal sides and six equal
angles. To lay out a hexagon, refer to Figure 4-21
and follow these steps.
1. Find the length of one side of the hexagon.
Half the diagonal Half the diagonal
Half the diagonal
A
A
Half the diagonal
Figure 4-18. Using outside calipers to make
precision measurements of a piece being turned on
a lathe.
Figure 4-19. Templates are useful for marking
unique designs on wood stock.
Figure 4-20. Layout of an octagon. The sides of
the square are equal to the distance across the
octagon. The radius of the arcs is equal to half the
diagonal of the square.
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