Answer:
The perimeter of this figure can be found by counting the number of 0.5 lines it takes to go one full circle around the figure.
In this case, there are 42 of these 0.5 lines.
So, if there are 42 of these 0.5 lines, the perimeter of the figure would just be: 42 times 0.5, which is equal to 21 cm.
Let me know if this helps!