Answer:
Part 1) b=2
Part 2) GH=9 units
Explanation:
we know that
If H is between G and I
then
-----> by addition segment postulate
Solve for GH
-----> equation A
step 1
Find out the value of b
we have

equate the equations

solve for b
adds 5 both sides

Divide by 4 both sides

step 2
Find out the value of GH
substitute the values
substitute the value of b