Step-by-step explanation:
Length of green line = length of black line
Length of green line = 26
Total length of black line = h + h + *
Total length of black line = 2h + 8
Equate the two expressions
26 = 2h + 8
Collect the like terms
26 - 8 = 2h
18 = 2h
Isolate h by dividing both sides by 2
18/2 = 2h/2
h = 18/2
h = 9
The equation is 26 = 2h + 8