Answer:
first is 20 second is 40 third is 60 and last is 80
Step-by-step explanation:
Answer:

if you don't its still right though
Step-by-step explanation:
only if you don't simplyfy if you do then just subtract and you will get a another answer which both are right
As a engineer who was mechanical then electrical most buildings, schematics,etc require some form of calculation for some shapes seeing that those shapes are what make up the world. Say for example you need to make something like a mother board pro house knowing it's shape and angle helps make a more accurate structure during the blue printing and build phase. No one just goes in and wings it you need to determine angles for things you don't know that the point of it.