Draw a large X. Extend the feet so its base is wider than its top. Plant four trees at the ends of the X lines and one where the two lines cross. Draw two lines from the two bottom trees up to the two outer top trees and continue the lines till they meet. Plant a tree there.
Four rows of trees, with three trees in each row. QED.
Three of the trees are the vertices of an equilateral triangle, three more trees are the midpoints of the triangle's sides and the seventh tree is the centroid.
54
to protect from wind erosion
Arrange them in the shape of a star with a pentagram at the centre... One tree at each outer point of the star, with another tree at the corner of the pentagram. Each liner of four trees is formed by two points of the star, and two corners of the pentagon.
An equilateral triangle with three trees at the angles, 3 bisecting the legs and one directly in the center.
Six ways. 15 rows of 2 trees 6 rows of 5 trees 3 rows of 10 trees and 2 rows of 15 trees 5 rows of 6 trees 10 rows of 3 trees * * * * * How about 1 row of 30 trees and 30 rows of 1 tree each?
20 trees
If someone plants 20 rows with 4 types of plants, they planted a total of 20 rows. If someone plants 20 rows of each of 4 types of plants, they planted a total of 80 rows.
windbreaks
Quincunx method - this is like square method with a tree placed in the center of each of the squares. Some variations may be done by planting the trees closer together in rows rather than having the rows apart. Trees planted at the center are temporary or fillers.
Sparky had room for 16 rows in his garden He planted 3 rows of tomatoes for every 5 rows of onions He planted 10 rows of onions.
Sparky had room for 16 rows in his garden He planted 3 rows of tomatoes for every 5 rows of onions. 6 rows of tomatoes were planted.
He planted 10 trees in the shape of a 5 pointed star.If there were 5 trees in a row then 5 x 4 gives you the answer.