A farmer is building a square pen 21 feet on each side. He puts one post at each corner and one post every three feet in between. how many posts will he use. please give equation
28 post
To find the number of posts, we need to determine the number of posts on each side of the square and then sum them up.
First, let's calculate the number of posts on one side of the square. The length of one side is 21 feet. The farmer puts one post at each corner, so that's 4 posts. Now, we need to calculate the number of posts in between the corners.
The distance between two corner posts is 21 feet. We need to divide this distance into equal intervals of 3 feet in order to determine the number of posts in between.
To find the number of intervals, we can divide the total distance by the interval length: 21 feet ÷ 3 feet = 7 intervals.
Each interval between the corner posts requires one additional post. So, the number of posts on one side (including corner posts) is 4 (corner posts) + 7 (intervals) = 11 posts.
Since there are four sides to the square, we can multiply the number of posts on one side by 4 to find the total number of posts: 11 posts/side × 4 sides = 44 posts.
Therefore, the farmer will use 44 posts in total.
In equation form:
Let P be the total number of posts.
Let S be the length of one side of the square.
P = 4 + (S ÷ 3) + 4(S - 1) = 44
There will be one post at each corner. One each side there will be posts at 3, 6, 9, 12, 15 and 18 — 6 posts on each side counting from a corner post.
I won't do the problem for you, but does this help?