Answer:
Electric TV, Airplane, Refrigerator, Computer, Steel
Step-by-step explanation:
Electric TV, Airplane, Steel, Refrigerator, Mechanical Computer
According to google:
Airplane (1903)
Steel (1850s)
Electric TV (1927)
Mechanical Computer (1822)
Refrigerator (1834)
A. 1
no it is not a right angle triangle