The scale of the drawing is 1 cm to 10 feet. This means, every 1 cm of the drawing represents 10 feet in actual.
The trees are 5.2 cm apart in the drawing. So according to the given scale, they will be 5.2 x 10 = 52 feet apart in actual.
So actual bushes be planted at a distance of 52 feet.
Try this option:
1. the sides of the biggest triangle are 16; x and √(16²-x²); the sides of the smallest triange are x;5 and y. The smallest triangle ~ the biggest triangle. Using the property of the similar triangles:

2. according to the Pyphagorean theorem (in the smallest triangle):

answer: y=√55.
See the photo attached for the answers