The heights of a certain type of tree are approximately normally distributed with a mean height = 5 ft and a standard deviation

I’m confused as to what you are asking 66 2/3 percentage wise

Ineed show the photo because i need more information

Use pythagorean’s theorem and find the missing side lengths of the two smaller triangles and add them together
13^2 - 12^2 = 5
15^2 - 12^2 = 9
5+9 = 14
14 is the length of each side of the square
14^2 + 14^2 = 19.8
19.8 is the diagonal length of the inside if the square