Solveit

$A_{circle}=\pi r^2\\ d_{circle}=2r$

$d_{circle}=2r\\ r=\frac d2\\ A_{circle}=\pi \times (\frac{d}{2})^2\\ A_{circle}=\pi \times \frac{d^2}{4}$

if you have two points on the graph you can pass a line through them and guess but to say it exactly it is too hard

Formula of slope:

$m=\frac{y_2-y_1}{x_2-x_1}$

3 machines can fill 80 boxes in 2 hours

$(\times\frac53)$                  $(\times\frac{15}{8})$

5 machines to fill 150 boxes in x hours

So look machines are inversely propotional more machines less time but boxes are directly proportional more boxes more time:

$2h.\times\frac35\times\frac{15}{8}=\frac94h.\;(or\;2.25h.)$

yes, you are right ! :)

hmm..

but it is increasing by 7,17 %, monthly

$7718\times 1.0717^x=y\\ x-number\;\ of\;\ month \\ $

$7718\times 1.0717^{19}=28767.1$

Thank you Melody and Guest ! :)

asin(inverse sin) will give you angle A:

asin(4/5) = 53.130102354156

A=53.130102354156

sqrt(32) = 5.6568542494923802

"2nd button"

 atan(0.57735026918962570 = 30 (deg)