Answer:
x=3 and y=2
Step-by-step explanation:
1.) 4x+3(5x-13)=18
expand into 4x+15x-39=18
18+39= 57
15x+4x= 19x
57/19= 3 so x=3
substitute 3 into y= 5x - 13
and you get 2 so y=2
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.
The formula for the radius is

so the answer would be 6 inches
Answer:
The ratios are both identical. (4 over 5 and 4 over 5)
Step-by-step explanation:
Th picture below represent the image you are referring.
sin x = opposite / hypotenuse
opposite side = 4
hypotenuse = 5
sin x° = 4/5
cos y° = adjacent/hypotenuse
adjacent = 4
hypotenuse = 5
cos y° = 4/5
The ratios are both identical (4 over 5 and 4 over 5)