Look at the pictures of watchtowers and any other types of watchtowers that you can find in books or on the Internet. On your own, list the advantages and disadvantages of each design. Then, draw initial idea sketches of your watchtower.

The lamppost must be between 4 m and 6 m tall. Choose $h = 5$ m total height.

$$h = 5 \, \text{m}$$

Pole height = 4 m (leaves 1 m for arm and light).

$$h_\text{pole} = 4 \, \text{m}$$

Use regular hexagon ($n=6$ sides). Side length $s = 0.4$ m.
Perimeter $P = n \times s$.

$$P = 6 \times 0.4 = 2.4 \, \text{m}$$

Arm has 3 bends (4 straight sections), total arm length 0.8 m. Each section $l_\text{section} = 0.2$ m.

$$l_\text{section} = \frac{0.8}{4} = 0.2 \, \text{m}$$

Sphere with diameter $d = 0.2$ m, radius $r = 0.1$ m.

$$r = \frac{0.2}{2} = 0.1 \, \text{m}$$

Pole drawing height: 4 cm.
Total height drawing: 5 cm.
Base side drawing: 0.4 cm.
Arm section drawing: 0.2 cm.
Light diameter drawing: 0.2 cm.

Final design summary: Total height 5 m, base perimeter 2.4 m, scale 1 cm $= 1$ m.

5 m