I believe he should add 2ft to the height of the tree as well
The unknown side lengths are
Large triangle 10
Medium triangle 2
Small triangle 12/5 or 2.4
Step-by-step explanation:
EFD to ABC is 0.4 or 2/5
EFD to GHI is 0.24 or 6/25
ABC to GHI is 0.6 or 6/10
2-1/4
2/1=8/4 Multiply top and bottom by 4
8/4-1/4
7/4
1 3/4