How many fence posts will you need around a triangle-shaped plot with sides 20, 20 and 30

How many fence posts will you need around a triangle-shaped plot with sides 20, 20 and 30 if the distance between the posts is 5m

Before solving the problem, we must understand that at the vertices of the triangle, the same column will be the basis for the next side where the fence will be attached. Now we count how many columns are needed in the total perimeter:
P = 20 + 20 + 30 = 70cm
Qty. columns = 70/5 = 12pcs.
From this amount, you need to subtract 3 vertices and add 1 to get started, we get the answer:
12-3 + 1 = 10pcs.
Answer: you need 10 columns.