Answer:
Part 4)
Part 5)
Part 6)
Step-by-step explanation:
Part 4) Find ER
we know that
In the right triangle ERF
Applying the Pythagorean Theorem
substitute the given values
solve for ER
Part 5) Find DF
we know that
In the right triangle DRF
Applying the Pythagorean Theorem
substitute the given values
simplify
Part 6) Find DE
we know that
----> by segment addition postulate
we have
substitute