The food service gave out 80 samples, which is 4 fewer than 70% of the total number of samples they prepared. Lets make x the total number of samples they prepared.
So lets write it as an equation
80 = (70% of x) -4
70% converts to a decimal by moving the decimal point 2 spaces up, so it is 0.7
80 = 0.7x-4
Add 4 to both sides of the equation
84 = 0.7x
Divide both sides by 0.7 to isolate the x
x = 120
The food service prepared 120 samples.
Complementary angles add up to 90 degrees.
The complement of 57 is (90 - 57) = 33 degrees.
this is answer for your problem
To find the length of the missing side, subtract all of the known side from the perimeter.
14 + 19 + 25 = 58.
73 - 58 = 15.
The fourth side is 15 feet
I hope that helps!