I need help on question 4 my test is tomorrow and I don’t understand

Answer:
The answer to your question is: Triangle 4
Step-by-step explanation:
Triangle 1 = 50 in
Triangle 2 = 0.8(50) = 40
Triangle 3 = 0.8(40) = 32
Triangle 4 = 0.8(32) = 25.6
25.6 in < 29 in